Please read: Posts on 19" rims

[rmp]

Hello all

Your friendly moderator here!

Of late just about every thread has somehow turned into the same discussion about 19" rims and tyres and this is starting to affect the readability and diversity of the forum.

We have now discussed the topic to death -- please search for the existing threads and read those.

For the next couple of weeks I will close any thread that wanders off topic into yet another 17-19" rim discussion because we need to keep the forum fresh and interesting.

If you have something else to add to the subject that hasn't already been discussed in detail feel free to create a new thread so those that aren't interested in it can at least avoid it easily.

I would also like to publically thank ozscott and gghaggis for resolving their differences amicably in a recent thread, which of course on further examination turned out to be not very much of a difference at all.

Thank you all and I look forwards to reading interesting posts that don't start with "but what about my 19" rims...."

[VladTepes]

but what about my 16" rims ?

(that different enough for you? It's a Defender of course).

[rmp]

As long as it's discussed here and you don't go perverting a discussion on say leather seats into rim sizes that's fine ;-)

[Slunnie]

3 posts and its already gone from 19" rims to Leather seats in Defenders! :mad:

[ozscott]

Fair enough rmp. I dont like slanging in any forum and I conceded that my early remarks in that other thread were inflammatory (and I explained later why that was so). Ghaggis and I showed 2 important things in that thread...we are both passionate about LR's and we were both able to put up sensible views and reach some common ground which (added to all the other enthuastic threads here) proves that LR owners are indeed a diverse lot with a sensible and pragmatic view of things! Its also quite acceptable to squabble in the LR family, but if a Toyo owners starting slanging at the 19 inch wheels on a D4 I would be all over them like a cheap suit.

Cheers

[rmp]

3 posts and its already gone from 19" rims to Leather seats in Defenders! :mad:

There's no issue with threads going off topic, that's just what they do, it's when they all go off topic to the same end that it becomes a problem ;-)

[Slunnie]

There's no issue with threads going off topic, that's just what they do, it's when they all go off topic to the same end that it becomes a problem ;-)
Just mucking around. :D

[Forest]

Brilliant, now about my 18's........:wasntme:

:eek: :p



I agree Rob, enough said.

[Disco4SE]

I know the 19" rims have been done to death, but I just thought I would let others know that yesterday when I was in at ULR Melbourne having the Q093 upgrade done, I mentioned the rim saga to the MD. He was unaware of the extent of interest and is going to approach LR to investigate an 18" option for the 3.0Lt. Keep you posted.
Not too posted though, I may get boooed off the forum!

[chuck]

That is a fantastic idea.
Perhaps we could get one of our moderators to organise a petition or a poll to forward to Landrover.

We already know that 18" rims can be manufactured to fit the 3.0 lt D4.

If we give them the details we have then given them a solution.

We could then forward this to the other specialist landrover forums to gain even more momentum.

Regards

Chuck

[Landover]

3 posts and its already gone from 19" rims to Leather seats in Defenders! :mad:

He mentioned 19" rims, you will have to close this thread now.:wasntme:

[rmp]

It's ok in this thread (or any thread devoted to the topic), it's every other thread I'm concerned about.

Re the petition -- good luck. It doesn't have to be a moderator by the way. There is always much less real support for a given idea than people who think it is a good idea. The latest in a very long line of examples was the fact that ggh was unable to raise even 15 people to pony up for the G-Max rims.

[Disco4SE]

Isn't it funny rmp.
So many people bitching about the 19" rims and wished the D4 3.0 had 18" rims, yet Gordon can't even get 15 sets together to place an order?????
How about those people put their hand up for a set!

[Tombie]

No whats funny is all the bloody ho-har about what essentially becomes 0.500" of sidewall... Thats about the height of THIS emoticon :wallbash:

OK so right now there arent 20+ varieties of rubber for the vehicle.
But then there werent a lot of 16" or 17" sizes not so long ago...

Then theres those who purchase a $75k+ vehicle and yet complain about $500 a corner rubber... :wallbash::thumbsdown:

Deal with it people! Move on.... Its a tyre on a rim..... Technology has moved on, tyres are better now than they were back in the days of 15" rims... Better compounds, constructions etc...

How about just driving the damn thing?
:tease:

[rmp]

Isn't it funny rmp.
So many people bitching about the 19" rims and wished the D4 3.0 had 18" rims, yet Gordon can't even get 15 sets together to place an order?????
How about those people put their hand up for a set!

Yep. I've organised a few forum things and I can tell you there is a pyramid of support for any given idea. When you ask for actual money or commitment that's when people suddenly look away. Not that I wish to discourage such efforts which have had notable successes, it's just a cautionary tale. Good on Gordon for giving it a shot, you have to respect that.

[scarry]

That is a fantastic idea.
Perhaps we could get one of our moderators to organise a petition or a poll to forward to Landrover.

We already know that 18" rims can be manufactured to fit the 3.0 lt D4.

If we give them the details we have then given them a solution.

We could then forward this to the other specialist landrover forums to gain even more momentum.

Regards

Chuck

We could go on about this for ever............

But wouldn't we be better pushing for 17' rims,as these would be a bigger jump in size & more suitable for those that want to run larger rims on the D4 3.0l.
I realise the vehicle would need more changes than going to 18's,& could probably only be done by LR.

Surely there is a design that won't compromise braking effectiveness,that would allow for 17's

But,does LR ever listen to it's customers?

Just my 2 cents worth

[gghaggis]

We've shown (as a proof of concept) that you can build 18" rims to fit without modifying the car at all. I don't think this would be true of a 17" rim - you would have to downgrade (or severely re-design) the brake package. There just isn't enough clearance

Given that choice (and a gun to their head), I'd imagine that LRA would find the former far more palatable.

Cheers,

Gordon

[Tombie]

We could go on about this for ever............

But wouldn't we be better pushing for 17' rims,as these would be a bigger jump in size & more suitable for those that want to run larger rims on the D4 3.0l.
I realise the vehicle would need more changes than going to 18's,& could probably only be done by LR.

Surely there is a design that won't compromise braking effectiveness,that would allow for 17's

But,does LR ever listen to it's customers?

:soapbox:

This is not a personal attack - do not take it as such, I quoted the above because it raises good points. And are valid questions from the owners perspective - In my view these questions are based on heresay rather than experience in real world situations.. (Think ala 2" lift - almost everyone who gets a new 4wd mentions a 2" lift!)


Firstly vehicles have to have stronger brakes the more power they produce. This is not about speed, its about the ability to decelerate a vehicle which can accelerate quicker than lesser powered versions.

Then theres ventilation, a large rotor requires air flow around it to cool the brakes. The larger rotor also requires a larger caliper and this consumes room necessitating larger rim diameters / clearances.

Then, we have the 'car like' drivability of a modern 4wd, people throw them around like a car, forgetting the 2500kg they have to slow. A 3.0L accelerates quicker and therefore needs to slow faster once the inertia is built....

Larger rotors allow a larger swept surface for brakes, smaller surfaces work harder for the same effort, resulting in faster brake wear rates.

Land Rover, like all other (I hate this term) SUV manufacturers has listened to the market... A car like, 2500kg people mover with offroad capability and modern styling has been built. To think that the Australian market constitutes more than a drop in a bucket to the global sales base is laughable. Soccer Mums the world over love their big, car like SUV and its great brakes and larger rim tyre combo with responsive steering and handling.

Whats more surprising, is that the locals are looking to spend thousands of dollars on a 12.7->25.4mm profile change in their running gear. I mean were talking the need to slow your offroad pace less than 5km/h to protect the tyre compared to a slightly increased profile.

Ride and handling in these larger rims is affected by AIR VOLUME inside the rim/tyre combo... The tyre may be lower profile but the rim is shaped to provide an air chamber suited to a volume of air they wish it to hold. The air is the cushion for the most part (although sidewall construction plays a role) in the ride quality of the wheel assembly.

PROOF OF CONCEPT is easy to achieve, however, are you willing to also put in the tens of thousands of kilometers of testing to ensure that the rim is strong enough to take the pounding that the OEM has done?

ROH for example make a rim for earlier Landrovers - the ZF I think, which fits, works and under use fatigues and cracks...

To make a rim profiled internally to avoid the caliper means something had to give, the profile has been changed and the rim profile is not quite the norm! Nor is the clearances between rim and caliper.

Plenty of POC products fail to achieve in the real world unfortunately.

But still, we are talking - and I will laugh forever over this one... 12.7mm difference to the sidewall height going to an 18" rim.

How much more deflection do you honestly believe this 12.7mm will give offroad? At 80+km/h likely to be nothing noticeable. Better to get a tyre with a nice thick rim protector built into it...

ALL OF THIS EFFORT would be better put towards lobbying a tyre manufacturer to make a mould for a 19" tyre that is 25mm LARGER than OEM.

Considering the law generally allows a 25mm larger tyre this is the SAME gain in sidewall as the rim change, with the added benefit of increased rolling diameter.

You can then have the CCF modified to correct the speedo error back to zero.

Towing, with the larger brakes trapped inside smaller rims with lower airflow is my idea of a nightmare... A long downhill on the brakes will definitely heat them up more than running std rims...
Offroad, the extra debris that can be trapped inside the smaller rim (including rocks caught between caliper and rim) will cause more damage and wear than sticking to 19's...

Anyone ever seen a rock caught between rim and caliper? I have...
It nigh on carved the rim into 2 seperate pieces and the owner was lucky not to suffer a dangerous failure. Rim was cut over halfway through the alloy.

Let it rest, the vehicle is more than capable on 19's... Yes they are not as common right now - so buy a spare carcass before you go on that long trip... Get a repair kit and learn to use it. 19s, 18s, 17s and 16s make no difference... I've never staked a tyre offroad ever in any profile. And I'm offroad more than probably 90% of members here...

I've sat watching accredited trainers and cringed at the old school, old thinking methods used offroad... This is not a 1990s vehicle, its a 2010 vehicle.. Build using modern techniques and modern technologies including suspension and tyres.. Combined with modern materials used for recoveries today almost the entire 4wd handbook is outdated.
Same thinking applies to oils and filters.... People keep thinking like 1980 Landcruiser diesel owners... 5000km changes etc...

We really need to get this old school thinking out of our minds and catch up with the reality of the times...

And stop obsessing with bloody 19" rims would be a good start :whistling:

I'm sure I've just knocked someones nose out of joint...

[CSBrisie]

I went the 2nd set of rims option, 19's with GY MTR's (like ggh). I really think this is a great option; I have car like handling for the 90% of the time the car is used and then MTR's for off road - and I've heard nothing bad about the MTR's and am comforted by Landrover G4 Challenge specifying them which HAS to say something! Best part was the RRS 19" rims I got (and anyone else could from the same seller) were relatively cheap $295each and look great! The MTR's will last for ages and I thought were also reasonably priced ($495). The wheel tyre package is not cheap - given - but hey, neither was the car...

One day Conti's will bring out an GGAT2 in 19inch and I would swap to those when the D4's road tyres expire as they have been brilliant on and off road on the D3 (18inch).

So, I'm a happy tyre camper allround...so to speak...

[B92 8NW]

I've sat watching accredited trainers and cringed at the old school, old thinking methods used offroad... This is not a 1990s vehicle, its a 2010 vehicle.. Build using modern techniques and modern technologies including suspension and tyres.. Combined with modern materials used for recoveries today almost the entire 4wd handbook is outdated.
Same thinking applies to oils and filters.... People keep thinking like 1980 Landcruiser diesel owners... 5000km changes etc...

We really need to get this old school thinking out of our minds and catch up with the reality of the times...

And stop obsessing with bloody 19" rims would be a good start :whistling:

I'm sure I've just knocked someones nose out of joint...

Well said.

It's a baby boomer thing... wariness/fear of modern concepts, inflexible thinking, myopic belief that their own knowledge is gospel. Find any 60 or so year old house painter (like the one I've just had in), they'll argue till their blue in the face an oil based paint is more durable than an acrylic, they're not interested in being progressive, studying what the manufacturers are putting out, Orica and Wattyl give their flagship exterior acrylic paints a 15 year warranty, they don't give their oil based products any warranty at all, but still they'll use a oil based gloss on your (my) window frames.

It's great when you get a generic old school 4x4 instructor (ie NOT working exclusively with LR) that has no idea of the technology and advises, OOMA, disabling anti-stall or disabling TC and fitting lockers because their knowledge IS RIGHT and the technology is WRONG:rocket:

[gghaggis]

Well said Tombie2. As I pointed out in another thread, after trying them and seeing what they're capable of, I'm personally more than happy with the MTR's on 19" rims. The steel 18" rims I have will not be for general consumption - I'll consider using them in off-road trials etc.

I am only following through with the hunt for forged alloy 18" rims because I said I would - not because I believe they're necessary. And for those who want more choice in 19" tyres, note that GG are still committed to bringing out an AT2 in this size, and that other manufacturers have the larger 275/55/19 sizes available now in Europe (although at this stage only in HT and Winter styles). I would seriously consider the Dunlop WTM3 in that size if it was available here.

Cheers,

Gordon

[rmp]

Firstly vehicles have to have stronger brakes the more power they produce. This is not about speed, its about the ability to decelerate a vehicle which can accelerate quicker than lesser powered versions.


Sort of. Higher-performance brakes are fitted not because they are requried by law, but because it makes sense if you have a higher performance vehicle. The stopping distance tests could easily be met with far less braking capability than is fitted.




Then theres ventilation, a large rotor requires air flow around it to cool the brakes. The larger rotor also requires a larger caliper and this consumes room necessitating larger rim diameters / clearances.


That's just the current design. It is possible to make a high-performance brake which fits into a smaller rim. But it's more expensive for various reasons including as you point out pad wear, and most owners like the larger rims, so why bother.

The point about ventilation is why steel rims should be viewed with caution as these do not permit heat to dissipate as well as alloys.




Land Rover, like all other (I hate this term) SUV manufacturers has listened to the market... A car like, 2500kg people mover with offroad capability and modern styling has been built. To think that the Australian market constitutes more than a drop in a bucket to the global sales base is laughable. Soccer Mums the world over love their big, car like SUV and its great brakes and larger rim tyre combo with responsive steering and handling.


Precisely. The Aussie market is microscopic and the offroaders within that even smaller. So, we're not a significant influence.




Whats more surprising, is that the locals are looking to spend thousands of dollars on a 12.7->25.4mm profile change in their running gear. I mean were talking the need to slow your offroad pace less than 5km/h to protect the tyre compared to a slightly increased profile.


Put like that who could argue? But then measure the sidewall width. Then measure it when slightly aired down with the tyre contact patch accounted for. Then look at the percentage difference, and I'm taking 17 to 19mm here or 25mm as the debate is really 17s on D4 2.7 vs 19s 3.0. It's a significant percentage.




PROOF OF CONCEPT is easy to achieve, however, are you willing to also put in the tens of thousands of kilometers of testing to ensure that the rim is strong enough to take the pounding that the OEM has done?

ROH for example make a rim for earlier Landrovers - the ZF I think, which fits, works and under use fatigues and cracks...


That's a seperate discussion about all aftermarket accessories.






ALL OF THIS EFFORT would be better put towards lobbying a tyre manufacturer to make a mould for a 19" tyre that is 25mm LARGER than OEM.


That would help except that then you'd probably get clearance issues. And in Victoria and NSW it wouldn't be legal.




Considering the law generally allows a 25mm larger tyre this is the SAME gain in sidewall as the rim change, with the added benefit of increased rolling diameter.

You can then have the CCF modified to correct the speedo error back to zero.


15mm in Vic/NSW. 50mm elsewhere. Both limited by clearance. Given the push for ESC I think tyre diameter restrictions will just increase.




Towing, with the larger brakes trapped inside smaller rims with lower airflow is my idea of a nightmare... A long downhill on the brakes will definitely heat them up more than running std rims...


And if you've gone for larger diameter tyres that would have a similar effect. If you're going downhill for long periods of time then the correct techniques need to be used to avoid fade regardless of the brakes. You could say that as a bullbar, winch etc adds weight that also affects the braking required and it's true. This is just another factor.




Offroad, the extra debris that can be trapped inside the smaller rim (including rocks caught between caliper and rim) will cause more damage and wear than sticking to 19's...

Anyone ever seen a rock caught between rim and caliper? I have...
It nigh on carved the rim into 2 seperate pieces and the owner was lucky not to suffer a dangerous failure. Rim was cut over halfway through the alloy.


That can happen regardless of rim.





Let it rest, the vehicle is more than capable on 19's... Yes they are not as common right now - so buy a spare carcass before you go on that long trip... Get a repair kit and learn to use it. 19s, 18s, 17s and 16s make no difference... I've never staked a tyre offroad ever in any profile. And I'm offroad more than probably 90% of members here...


Agreed the vehicle is highly capable on the right 19s. It would be better offroad in 17s. But do you need that extra capability? Each to their own, for some the answer is no, for other yes.

The repair kits do not cover 19s now, at least the ones I've seen. I'm glad you've never staked a tyre! By repair kits I mean those to remove and repalce tyres from rims, not plugs which do work on any tyre except for really high-speed roadies which are too weak.




I've sat watching accredited trainers and cringed at the old school, old thinking methods used offroad... This is not a 1990s vehicle, its a 2010 vehicle.. Build using modern techniques and modern technologies including suspension and tyres.. Combined with modern materials used for recoveries today almost the entire 4wd handbook is outdated.


I agree there!

[Graeme]

Put like that who could argue? But then measure the sidewall width. Then measure it when slightly aired down with the tyre contact patch accounted for. Then look at the percentage difference, and I'm taking 17 to 19mm here or 25mm as the debate is really 17s on D4 2.7 vs 19s 3.0. It's a significant percentage.
Throw in the lack of LT tyres in 19"`compared with 17" and the 17" looks a good option except for the brake downsizing required. Give me 255/55-19 MTRs with Kevlar sidewalls and I'd risk the rim damage, as long as they're fitted to 19"x8" rather than 19"x9" rims and I had 2 spare rims.

[rmp]

There is a parallel to this debate for onroads. The decision I've taken to run all-terrains on 17s means my D3 doesn't perform as well as one on roadies using 19s. However, it's more than good enough for my purposes as I don't push the car's onroad limits, but I don't and can't argue I've lost nothing onroad.

In the same way, the 19" rim may be more than good enough for many offroaders and that's fine, but they can't argue no capability is lost or unrealised.

The brake downsizing isn't an issue for the 2.7 D3/D4 as no downsizing is required and the vehicles are designed for that size of rim. It's only an issue if you were to fit say 2.7L brakes to a 3.0L which would open up all sorts of interesting problems which I don't think would be cost-effective to solve.

255/55/19s probably aren't legal on 19x9 rims, need to check the tyre spec chart.

[scarry]

rmp & tombie,excellent posts








Precisely. The Aussie market is microscopic and the offroaders within that even smaller. So, we're not a significant influence.






True,but i would be surprised if this topic has not been raised in other parts of the world.

There are also other vehicles around with similar power & weight figures to the D4 running 17" rims,either as OEM or as an option.

[ozscott]

rmp has made all the points that need making on this topic I reckon - all well put.

Cheers

PS. The perspective of those who buy the D3/D4 will vary as to which is most important to them - ie on road or off road.

[rmp]

rmp & tombie,excellent posts




True,but i would be surprised if this topic has not been raised in other parts of the world.

There are also other vehicles around with similar power & weight figures to the D4 running 17" rims,either as OEM or as an option.

The percentage of people who take the vehicles offroad is very small, and unfortunately their needs are often opposed to the needs of the non-offroading majority. Therefore, the latter's priorities are more important.

[gghaggis]

I agree with all said on this page, but I'd like to point out that there is an implication being made here that might confuse or put off people considering the 3 ltr TDV6. That is, that it is not capable enough to satisfy some people's off-road desires. I don't think this is correct. In terms of pure off-road capability, I haven't felt any lessening of capability from moving from a 2.7 ltr D3 on 17" competition muddies to a 3.0 ltr RRS on MTR's.

In terms of tyre durability and availability, yes, the 17" rims have an advantage. This is one variable however, that will almost definitely change over time.

Cheers,

Gordon

[gghaggis]

rmp & tombie,excellent posts




True,but i would be surprised if this topic has not been raised in other parts of the world.

There are also other vehicles around with similar power & weight figures to the D4 running 17" rims,either as OEM or as an option.

There are very few other vehicles with 600Nm+ of torque that weigh as much as a D4 and are designed to go as well off-road. I can't think of any that come with OEM 17" rims? Edit: maybe the Porsche Cayanne?

Cheers,

Gordon

[rmp]

The LC200 weighs just as much, is as powerful as a TDV8 let alone a 3.0 D4 (certainly won't be left behind in a drag race) and comes with 17s standard in some specs. It also tows 3500kg and 750kg, another brake consideration. It has larger diameter tyres so say 18s on that car gives you more sidewall than 18s on say a RRS. It's really sidewall height is the issue, not the profile % which only gives an indication.

The VW Touraeg, relative of the Cayenne is another example. In its V6 diesel form it has a greater power to weight ratio than the TDV8 yet runs 17s. It is a little lighter though. The V10 monsters will slaughter any Land Rover diesel and I think they run min 19s or maybe 18s, I forget. They are just as heavy. Neither car is as good as the D4 offroad.

There is no need to run such large rims for brakes. It makes the job easier (cheaper) and looks better, but there is no engineering need.

Note that while the 200 has the raw grunt come the corners it'll flounder ;-)

[gghaggis]

The LC200 weighs just as much, is as powerful as a TDV8 let alone a 3.0 D4 (certainly won't be left behind in a drag race) and comes with 17s standard in some specs.


Well, most mag comparos have said otherwise - in favour of the D4 ;)


It also tows 3500kg and 750kg, another brake consideration. It has larger diameter tyres so say 18s on that car gives you more sidewall than 18s on say a RRS. It's really sidewall height is the issue, not the profile % which only gives an indication.

Yes, LR have always spec'd smaller tyres than the opposition - and made it difficult to upgrade without being illegal.


The VW Touraeg, relative of the Cayenne is another example. In its V6 diesel form it has a greater power to weight ratio than the TDV8 yet runs 17s. It is a little lighter though. The V10 monsters will slaughter any Land Rover diesel and I think they run min 19s or maybe 18s, I forget. They are just as heavy. Neither car is as good as the D4 offroad.

There is no need to run such large rims for brakes. It makes the job easier (cheaper) and looks better, but there is no engineering need.

I've never understood the 'greater acceleration = requirement for better braking' argument. The momentum of a vehicle is based purely on it's speed and weight. Its ability to get to a particular speed has nothing to do with it. There seems to be some 'rule of thumb' that a faster accelerating car is always driven at higher speeds, therefore requires better brakes??

Aside from that, you're missing the benefits of cooling and sensitivity that come with a larger surface area on the disc - important for cars that use the ABS system for traction control off-road. The D4 has better performance in this field than a lot of the competitors due in part to it's larger discs. However, this admittedly doesn't excuse it's poor caliper design, which is one of the other reasons for the larger rim requirement, so I'd agree with you there.


Note that while the 200 has the raw grunt come the corners it'll flounder ;-)

- it won't keep up on the straights either!!

Cheers,

Gordon

[Disco4SE]

I have a feeling that the LC200 is a couple of hundred Kg heavier than the D4. As metioned in another of my posts, the D4 when put on a dyno machine, has less loss of flywheel power to the wheels.
This is why the D4 is quicker to 100Klm per hour and is more nimble on straights and hills as well.

[Graeme]

However, this admittedly doesn't excuse it's poor caliper design, which is one of the other reasons for the larger rim requirement..
I think its the other way round, with LR's priority for a minimum sidewall height for better steering precision from less tyre squirm when hurtling around corners (part of their premiumness) so stuck bumps on the calipers and brackets to prevent fitment of smaller rims.

[rmp]

I have a feeling that the LC200 is a couple of hundred Kg heavier than the D4. As metioned in another of my posts, the D4 when put on a dyno machine, has less loss of flywheel power to the wheels.
This is why the D4 is quicker to 100Klm per hour and is more nimble on straights and hills as well.

No, it's not that much. The exact difference depends on the spec level and engine of the cars in question. They are pretty close. What makes more of a difference is the D4's gearing, the 200's 6th gear is very tall.

[rmp]

Well, most mag comparos have said otherwise - in favour of the D4 ;)


Having drag raced a TDV8 Vogue and a 200 diesel I know there's nothing in it. Others may have had the same personal experience and come to a different conclusion, I can't say.




I've never understood the 'greater acceleration = requirement for better braking' argument. The momentum of a vehicle is based purely on it's speed and weight. Its ability to get to a particular speed has nothing to do with it. There seems to be some 'rule of thumb' that a faster accelerating car is always driven at higher speeds, therefore requires better brakes??


OK I'll explain. Two reasons.

1. A faster accelerating car will have a higher top speed, in general, which means the brakes have a lot more work to do, quite a difference in slowing from 250km/h than from 180km/h. Manufacturers must design the brakes to match the top speed.

2. The quicker car will also be capable of being driven more quickly. Therefore, it will need to slow down more often. Take a windy road, where a slow car only makes it to say 80 on a short straight, the quick one gets to 100 every time. If you corner at the same speed there's a lot more energy to get rid of. Even non-sporting drivers keeping below the limit will end up quicker in say a RRS SV8 than a RRS TDV6 2.7, so more braking power needed. So yes there is a rule the faster the car the better the brakes have to be. The slow and fast cars may stop in the same distance from 100km/h (and there are road regs that give minima), it's really about combating brake fade and giving a more sporting drive to match the acceleration.


All that means a quicker accel car does indeed need greater braking capability. Whether or not it is legal to use that speed and power is not the point, nor is whether people will actually use it. In the same way, fast cars run tyres rated to 250-300km/h even though nobody will ever use that speed.

You are quite right that in the real world, pootling around at 100km/h as we do the braking capacity requried has nothing to do with the vehicle's acceleration capability, provided you don't drive it any quicker than the slower cars. But the car still needs to be designed to handle the loads it is capable of.




Aside from that, you're missing the benefits of cooling and sensitivity that come with a larger surface area on the disc - important for cars that use the ABS system for traction control off-road. The D4 has better performance in this field than a lot of the competitors due in part to it's larger discs. However, this admittedly doesn't excuse it's poor caliper design, which is one of the other reasons for the larger rim requirement, so I'd agree with you there.


I'm not missing any benefits at all, I'm well aware of the advantages of large brakes. My point is that large brakes are not required -- manufacturers could design smaller ones, but it's cheaper and easier to go for the larger ones for various reasons such as you points above and Tombie's earlier.





- it won't keep up on the straights either!!



Everyon's got their own experience, I'm not about to argue other people coming to a different conclusion to me. My experience is that the two are pretty close in straight-line grunt and I'm not bothered about 0.5 of a second in stats, I don't even know what the 0-100 times are for either, probably 10 secs I expect. The 200 feels slower though as it's noisier.

[CaverD3]

I think LR designed brakes for to 5.0L V8 and just used them for the 3.0L TDV6 as it was cheaper than designing new ones for it.
As they are the same as the V8 ones I would say they must be over speced for the 3.0L.
The old V8 discs on the 3.0L would allow you to fit 18 inch and would be the right spec for the power/speed.

[gghaggis]

I think LR designed brakes for to 5.0L V8 and just used them for the 3.0L TDV6 as it was cheaper than designing new ones for it.
As they are the same as the V8 ones I would say they must be over speced for the 3.0L.
The old V8 discs on the 3.0L would allow you to fit 18 inch and would be the right spec for the power/speed.

I suspect your right, but I like GraemeS' description - "We'll put fins on the calipers so those bugg*rs can't mess about with the rims" :D

Robert, thanks for the explanation of the "faster car, bigger brakes" rule. But how much I'd apply that sort of logic to the difference between a 2.7 ltr and 3.0 ltr D4 I'm not sure. A D4 and an Aston Marton, well yes!

I don't know what conditions you've raced a TDV8 and an LC200 with each other, so I can't comment. But in the mag comparos, they've all said pretty much the same thing - that the D4 just pulls away from the LC, quite significantly. I think the LC200 0~100 time is around 10s. The TDV6 3.0 is 9.3 and the TDV8 is 9.2

Cheers,

Gordon

[Disco4SE]

The old D4 V LC200 debate.
I dont suppose many have had the opportunity that I have, that is having a brand new D4 & LC200 for a whole weekend in my driveway, both with tow bars.
I beleive that this is the only way to compare the two. Hook up a trailer with one then the other on the same road, hills etc. Drive the same route that you are used to with one, then the other.
Having had three LC's and being a big fan, I went for the D4 3.0Lt.
I challenge anybody to do the same and tell me they prefer the LC.

[rmp]

The old D4 V LC200 debate.
I dont suppose many have had the opportunity that I have, that is having a brand new D4 & LC200 for a whole weekend in my driveway, both with tow bars.
I beleive that this is the only way to compare the two. Hook up a trailer with one then the other on the same road, hills etc. Drive the same route that you are used to with one, then the other.
Having had three LC's and being a big fan, I went for the D4 3.0Lt.
I challenge anybody to do the same and tell me they prefer the LC.

The 200 vs D4 as a general comparo has already discussed already here ->

http://www.aulro.com/afvb/d3-d4-rrs/104473-disco-4-v-landcruiser-200-a.html

we're discussing here acceleration only.

[rmp]

I suspect your right, but I like GraemeS' description - "We'll put fins on the calipers so those bugg*rs can't mess about with the rims" :D


:p indeed, but I never attribute to malice what can be explained by sheer negligence or not caring!




Robert, thanks for the explanation of the "faster car, bigger brakes" rule. But how much I'd apply that sort of logic to the difference between a 2.7 ltr and 3.0 ltr D4 I'm not sure. A D4 and an Aston Marton, well yes!


Yep, well the reasons are cars are the way they are....more to do with regulations and marketing than pure engineering.




I don't know what conditions you've raced a TDV8 and an LC200 with each other, so I can't comment. But in the mag comparos, they've all said pretty much the same thing - that the D4 just pulls away from the LC, quite significantly. I think the LC200 0~100 time is around 10s. The TDV6 3.0 is 9.3 and the TDV8 is 9.2

Cheers,

Gordon

Well I decided to go and check the figures. Turns out the 200 is 8.2 seconds to 100km/h. So, quicker than LR's best. I've done roll-on tests with a 200 vs a TDV8 Vogue and there was nothing significant between them, but the 200 was marginally ahead. Like I said others are welcome to their opinions, that's mine which is borne out by the stats. Perhaps they meant "left behind through the bends" -- I'd certainly agree there. Or maybe their roll-ons were such that the test managed to hit a sweet spot for the D4's engine and gearing combo.

Personally I don't think outright accel is a major factor anyway and there's so many variables involved, so I tend not to bother with it overmuch. The pleasure of a car is defined by much more than its ability churn your guts when you hit the loud pedal, for me at least.

[Disco4SE]

Hi rmp, Buying a 4WD is not about 0 - 100 Kph figures. I bought mine for towing, 4WD capabilities and day to day ease of driving.
However, whoever told you that a LC 200 TDV8 can reach 0 - 100 Kph in 8.2 seconds (as quoted in the movie "The Castle") 'tell him his dreamin'.

[rmp]

Hi rmp, Buying a 4WD is not about 0 - 100 Kph figures. I bought mine for towing, 4WD capabilities and day to day ease of driving.
However, whoever told you that a LC 200 TDV8 can reach 0 - 100 Kph in 8.2 seconds (as quoted in the movie "The Castle") 'tell him his dreamin'.

I agree, but seeing as the subject came up we may as well discuss it.

OK, I'll let the people at Toyota know they're dreamin'.

I think it's a bit optimistic myself, but that's the figure they quote and my own experience is that the 200 is lineball with the best LR diesels for straight-line grunt. But I'm repeating myself again....

[CaverD3]

I thought thewre was an issue with the torque output being rediced untill third gear which would explain the run on response being good but the initial excelleration being poorer than the D4 3.0.

[Celtoid]

OK I'll explain. Two reasons.

1. A faster accelerating car will have a higher top speed, in general, which means the brakes have a lot more work to do, quite a difference in slowing from 250km/h than from 180km/h. Manufacturers must design the brakes to match the top speed.


I'm not sure if I've mis-interpreted your comment here but accelaration has absolutely nothing to do with top speed whatsever. At the end of the day the possible speed created by the tourque and power of an engine is limited by the gearing/torque/power/drag ratio.

A vehicle with greater acceleration will just get faster quicker, even if it can't go above 100kph...so even around town, a car with less accelaration may not get to 60kph by the end of the street, where the vehicle with greater acceleration will....so it's brakes will/may be working harder more often. My physics is a bit rusty these days but I also think that even if you have just hit/passed a certain speed and are still accelerating, the brakes need to work even harder to deal with the extra energy that comes with reducing acceleration to a constant speed or to zero.

As I said, maybe I didn't get what you were trying to say. :)

Regards.

[rmp]

OK I'll explain. Two reasons.

1. A faster accelerating car will have a higher top speed, in general, which means the brakes have a lot more work to do, quite a difference in slowing from 250km/h than from 180km/h. Manufacturers must design the brakes to match the top speed.


I'm not sure if I've mis-interpreted your comment here but accelaration has absolutely nothing to do with top speed whatsever. At the end of the day the possible speed created by the tourque and power of an engine is limited by the gearing/torque/power/drag ratio.


Yes, I know, which is why I qualified it with "in general" just in case anyone called me on it ;-)

Despite that point being technically incorrect, in practice it does hold which is why I cited it -- I cannot recall a single vehicle with two engines where the more powerful one does not accelerater quicker and also have a higher top speed than the less powerful one. The top speed isn't usually a lot greater, thanks to the speed squared law of aerodynamics, but still more. The next reason I think is the bigger factor.





A vehicle with greater acceleration will just get faster quicker, even if it can't go above 100kph...so even around town, a car with less accelaration may not get to 60kph by the end of the street, where the vehicle with greater acceleration will....so it's brakes will/may be working harder more often.


Exactly. In some cases the less powerful car may not even need to brake for a corner having not exceeded the corner's speed, whereas the more powerful one will. This assumes that both cars have approximately the same cornering speed. In some situations even that point is moot, a red light is a red light so you need to stop, same for a T junction and many other situations.




My physics is a bit rusty these days but I also think that even if you have just hit/passed a certain speed and are still accelerating, the brakes need to work even harder to deal with the extra energy that comes with reducing acceleration to a constant speed or to zero.

As I said, maybe I didn't get what you were trying to say. :)

Regards.

OK now it's my turn to be confused...I think you're saying there that if you are accelerating as you hit 100km/h and then brake you'll use more energy than if you were steady at 100km/h and braked? Yes that is correct -- imagine you weren't going to brake to 0 at all but were acclerating really hard to a steady state of 100, you'd need to brake just to get to that stead state.

All this is quite arcane and I think the real reason manufacturers fit huge brakes (apart from the design advantages) is because the consumers like the look. Ostentantious aerofoils are out, writing "317kw" or "BOSS 290" on the side of the car is not everyone's cup of tea, so a nice big brake caliper with low-profile tyres is an understated way of saying this car is pretty damn quick.

[gghaggis]

Robert,

Where did you get the LC200 acceleration times from? If not from Australia, note that in different markets the LC is offered with different engine spec's and tune (look carefully at the quoted power outputs). I can't see any quoted specs for the LC on the Australian site, so I'm going from the road tests in Overlander and 4x4 Action, whom I presume (ever to my detriment) have some vague idea what they're doing :angel:

Cheers,

Gordon

[Celtoid]

Yes, I know, which is why I qualified it with "in general" just in case anyone called me on it ;-)

Despite that point being technically incorrect, in practice it does hold which is why I cited it -- I cannot recall a single vehicle with two engines where the more powerful one does not accelerater quicker and also have a higher top speed than the less powerful one. The top speed isn't usually a lot greater, thanks to the speed squared law of aerodynamics, but still more. The next reason I think is the bigger factor.





Exactly. In some cases the less powerful car may not even need to brake for a corner having not exceeded the corner's speed, whereas the more powerful one will. This assumes that both cars have approximately the same cornering speed. In some situations even that point is moot, a red light is a red light so you need to stop, same for a T junction and many other situations.




OK now it's my turn to be confused...I think you're saying there that if you are accelerating as you hit 100km/h and then brake you'll use more energy than if you were steady at 100km/h and braked? Yes that is correct -- imagine you weren't going to brake to 0 at all but were acclerating really hard to a steady state of 100, you'd need to brake just to get to that stead state.

All this is quite arcane and I think the real reason manufacturers fit huge brakes (apart from the design advantages) is because the consumers like the look. Ostentantious aerofoils are out, writing "317kw" or "BOSS 290" on the side of the car is not everyone's cup of tea, so a nice big brake caliper with low-profile tyres is an understated way of saying this car is pretty damn quick.

I think we're on the same page Robert. Same car, different engine and in most cases you'd probably be right...gearing aside I guess.

I was thinking of the case like a motocross bike...brilliant acceleration and out of puff at 100....LOL!!!!

My point is, there are a lot of variable that create speed and acceleration and there isn't always a proportional or direct link....even in the same chasis.

Regards,

Celtoid

[Celtoid]

OK guys,

Getting back to the topic of 19" Rims and trying not to start another 'size war'......

I'm off to Fraser Island in a few weeks with a stock standard D4 SE 3.0TD. I'm running the standard 19" Rims with the Goodyear Wrangler tyres that the car came with.

I'm a tad confused with all the toe'ing and fro'ing over the tyres. I'm anticipating soft and hard sand work....what am I doing with my tyres? :confused:

Had I never read any of the threads on this topic I would have assumed I'd drop pressure whilst on the sand but I'd be asking to what pressure?....now that I have read the various opinions, not quite sure what to do. The car will be full of people and stuff but no trailer as we are staying at a house. Now I'm not so sure of the benefits of dropping pressure on a lower profile tyre.

Can somebody with real experience on this topic i.e. who has used tyres this size, clear this up for me please? :)

Drop pressure YES/NO?

What pressure to, if yes?

Thanks.

Regards,

Celtoid.

[Tombie]

OK guys,

Getting back to the topic of 19" Rims and trying not to start another 'size war'......

I'm off to Fraser Island in a few weeks with a stock standard D4 SE 3.0TD. I'm running the standard 19" Rims with the Goodyear Wrangler tyres that the car came with.

I'm a tad confused with all the toe'ing and fro'ing over the tyres. I'm anticipating soft and hard sand work....what am I doing with my tyres? :confused:

Had I never read any of the threads on this topic I would have assumed I'd drop pressure whilst on the sand but I'd be asking to what pressure?....now that I have read the various opinions, not quite sure what to do. The car will be full of people and stuff but no trailer as we are staying at a house. Now I'm not so sure of the benefits of dropping pressure on a lower profile tyre.

Can somebody with real experience on this topic i.e. who has used tyres this size, clear this up for me please? :)

Drop pressure YES/NO?

What pressure to, if yes?

Thanks.

Regards,

Celtoid.

Drop = Yes

Start around 22psi
Go lower if needed.

Don't forget to turn off DSC *every* time you re-start the vehicle.

[D3Watty]

Hi Celtoid,

I realise that the rim/tyre size is slightly different from the D4, but I recently took my 2.7l SE D3 to Moreton Island. With the standard 255 60 18's I ran the tyres at 20 psi and had no problems. Heading off the barge the D3 was fully loaded with camping gear and 4 big blokes and she never missed a beat.

Cheers,
Brett

[Celtoid]

Hi Celtoid,

I realise that the rim/tyre size is slightly different from the D4, but I recently took my 2.7l SE D3 to Moreton Island. With the standard 255 60 18's I ran the tyres at 20 psi and had no problems. Heading off the barge the D3 was fully loaded with camping gear and 4 big blokes and she never missed a beat.

Cheers,
Brett

Thanks mate, appreciate the help.

Celtoid

[Disco4SE]

Hi rmp, sorry to go over old ground again, but Gordon is right with the 0 - 100 Kph figures for the 200 LC. It is actually a full second slower than the 3.0Lt D4.
Toyota Australia are dreamin

[gghaggis]

These days, most of the clients we take out on training have 19" rims fitted to their cars. Usually 255/55/19 or 255/50/19. On beach/sand dunes we tell them to drop the pressure to 16psi. Note the sand is fairly soft, on harder-packed surfaces you could leave them at 20psi. Obviously you need to be aware of sudden changes in direction such as hard cornering at speed, and negotiate rock outcroppings carefully (drive over rocks rather than scrape past them).

Other than that, these tyres at lower pressure will give you plenty of flotation - they extend their footprint in sand just as readily as 18" tyres. And the D4 3.0 ltr will have more than enough power to keep out out of trouble.

Cheers,

Gordon


OK guys,

Getting back to the topic of 19" Rims and trying not to start another 'size war'......

I'm off to Fraser Island in a few weeks with a stock standard D4 SE 3.0TD. I'm running the standard 19" Rims with the Goodyear Wrangler tyres that the car came with.

I'm a tad confused with all the toe'ing and fro'ing over the tyres. I'm anticipating soft and hard sand work....what am I doing with my tyres? :confused:

Had I never read any of the threads on this topic I would have assumed I'd drop pressure whilst on the sand but I'd be asking to what pressure?....now that I have read the various opinions, not quite sure what to do. The car will be full of people and stuff but no trailer as we are staying at a house. Now I'm not so sure of the benefits of dropping pressure on a lower profile tyre.

Can somebody with real experience on this topic i.e. who has used tyres this size, clear this up for me please? :)

Drop pressure YES/NO?

What pressure to, if yes?

Thanks.

Regards,

Celtoid.

[isuzurover]

I agree, but seeing as the subject came up we may as well discuss it.

OK, I'll let the people at Toyota know they're dreamin'.

I think it's a bit optimistic myself, but that's the figure they quote and my own experience is that the 200 is lineball with the best LR diesels for straight-line grunt. But I'm repeating myself again....

Toyota LC 200
Toyota 200 Series LandCruiser - www.drive.com.au (http://www.drive.com.au/editorial/articleDetail.aspx?articleID=47213)

Price


From $69,990.

Engine Size/Type


4.5-litre, direct-injection, twin-turbo, diesel V8.

Power


195kW at 3400rpm.

Torque


650Nm from 1600-2600rpm.

Brakes


Discs with anti-lock and stability control.

0-100km/h


10.5 seconds.


Land Rover D4 TDv6
The New Discovery 4 10MY | Land Rover Australia (http://www.landrover.com/au/en/lr/about-land-rover/news-overview/the-new-disco-4-10my/)

Responsive 500Nm Torque from idle in 500ms, delivers immediate throttle response and effortless cruising ability (0-100 km/h in 9.6 seconds, 24% improvement)

[rmp]

Re the 200 -- Toyota specs and they didn't say which country it applied to nor did I ask. I know there are differences between country spec levels and tune, and not only that there should be slightly different figures for trim levels too given there are weight differences. 8.2 does seem too fast and I agree 10 feels more logically nearer the mark, but there's a big gap between the 8.2 and 10.5 which has to be more than just spec difference. I would expect the D4 to win on paper as it has the better gearing for acceleration, a lower sixth gear.

I will say that you can't always trust manufacturer figures on a website or from anywhere else, very often you get different answers to the same question from different yet "official" sources. Have LRA confirmed the figures for the D4 are for AU cars in AU? Just because an Australian operation quotes a figure doesn't mean to say they have re-run a test with the AU spec model using AU spec fuel -- they do for fuel consumption and to get ANCAP test results, but for non-regulated figures like 0-100...doubt it especially for 4WDs. So, any figure like this is open to intepretation unless it's for a general idea.

I don't know what circumstances the mag tests were done in so won't comment. I'm not saying they're wrong by any means, maybe their test was such that the D4 won that contest, I only did roll-ons with a Vogue which has a slightly more powerful engine than the 3.0. I've explained my personal experience which was hardly scientific but would have shown up any major differences, and note that in these things context is everything (and I have no context for the mag tests referred to), so that's where I'll leave it and am unlikely to investigate it further given it's not a major buying consideration. I might speculate and say that the Toyota is certainly slower-revving so off the line would be slower and wouldn't be able to catch up. This is less of a problem with roll-ons. The end speed is also a factor, maybe they went to 80...100...150! A given vehicle could win one sector and lose another. In the real world, IMHO, there's not very much difference in straight-line grunt.

19s and low pressure -- x2 to Tombie and Gordon.

Celtoid - ok there's a whole other discussion about torque, drag, gearing etc about why a dirtbike accelerates quickly but doesn't have a high top speed, but that's a Technical or Campfire topic. The case of say a Lotus Elise and a heavy grand tourer like a Jag XK is another contrast. You're quite right but my point was about roadcars of the same type, different engines. And I agree we're on the same page here!

[Graeme]

I would expect the D4 to win on paper as it has the better gearing for acceleration, a lower sixth gear.
6th gear wouldn't get a look-in up to 100 kph - it probably only needs 3rd!

[Celtoid]

These days, most of the clients we take out on training have 19" rims fitted to their cars. Usually 255/55/19 or 255/50/19. On beach/sand dunes we tell them to drop the pressure to 16psi. Note the sand is fairly soft, on harder-packed surfaces you could leave them at 20psi. Obviously you need to be aware of sudden changes in direction such as hard cornering at speed, and negotiate rock outcroppings carefully (drive over rocks rather than scrape past them).

Other than that, these tyres at lower pressure will give you plenty of flotation - they extend their footprint in sand just as readily as 18" tyres. And the D4 3.0 ltr will have more than enough power to keep out out of trouble.

Cheers,

Gordon

Cheers Gordon, that's the sort of specifics I was looking for.

I realise that you are in Perth and may not know where to buy here in Brisbane but can you make a compressor recommendation?

Also, what's your thoughts on the 'track' style anti-bogging device...the plastic mat things that you stick under your tyres?

Regards,

Kev

[rmp]

6th gear wouldn't get a look-in up to 100 kph - it probably only needs 3rd!

True, I wasn't very clear...I was referring to the closer ratios by virtue of the lower top. Probably both are in third at 100 but I suspect the 200 wouldn't be as close to its 4th gear as the D4. Conversely, the 200 probably has a higher top speed thanks to the taller gear and mountain of torque (and yes I know there are many other factors!)

[Graeme]

and yes I know there are many other factors!.. such as the D4's speed limiter.

[Disco4SE]

Gear ratio's, fuel, manufacturers claims etc etc etc. All this bull$^*# aside (as mentioned in this post) I had the LC 200 and the D4 side by side for a whole weekend. Both new with similar Klm's. Towing and non towing.
Sorry, but the D4 is not only quicker (with or without towing) but it pulled stronger up the same hills.
You cannot argue with facts

[Celtoid]

.. such as the D4's speed limiter.

Speed Limiter???

I chuckled when I read in the manual about the suspension dropping at 160kph....that's the sort of speed I do before the end of my driveway....;)....LOL!!!

Who drives a 2.5t car like that? :)

So seriously, what speed is it limited to? Is that an Australian Spec?

[jonesfam]

Well, getting back to 19" rims I have just ordered 5 new Continental tyres to replace the Wranglers due to having 2 rock strike flats in 8 months. Don't know if the Conti's will be any better but I I have had no flats for years (except nails) so I'm trying something different to see if it works.
If it's a profile issue? Maybe I could swap someone my 19's for 18's? Someone that doesn't drive on rocky roads.
I will let you know how they go when they get here & get fitted.
Jonesfam

[Graeme]

Speed Limiter???

I chuckled when I read in the manual about the suspension dropping at 160kph....that's the sort of speed I do before the end of my driveway....;)....LOL!!!

Who drives a 2.5t car like that? :)

So seriously, what speed is it limited to? Is that an Australian Spec?
I hit 120 going across a paddock on my 19" Pirelli ATRs (19" content:D) because I couldn't go faster than about 80 going around it sticking to my driveway. Only 120 because its hard to stop down-hill on slippery wheat stubble. Speed is limited to 180 kph.

[Celtoid]

I hit 120 going across a paddock on my 19" Pirelli ATRs (19" content:D) because I couldn't go faster than about 80 going around it sticking to my driveway. Only 120 because its hard to stop down-hill on slippery wheat stubble. Speed is limited to 180 kph.

Good job you don't have a long straight drive way...:)

Thanks.

[gghaggis]

D4 diesel should be limited to 190kph? Still a mite bit faster than I'd feel comfortable with!

Regarding acceleration times, I did mine on a series of runs at the V8 Supercar track here in Perth and a std 3.0 ltr will average 9.3 to 9.5 sec for the 0~100kph dash. Sport mode was actually faster than command-shift.

I don't think a rolling start would make much difference - the LR is even better at the 50 ~ 100 kph times.

In Europe there is a choice of tune for the LC200. There will soon be the same for the LR 3.0 ltr, as they phase out the 2.7 ltr and the TDV8 3.6 ltr.

Cheers,

Gordon

Edit: Sorry, I should point out that my figures were for a 3.0 ltr RRS, not a D4

[gghaggis]

Your right - I wouldn't know where/what to buy in Brisbane! But my experience is that the top of the line compressors last around 3 ~ 4 years of reasonable use for around $400 (ARB, BlueTongue etc) whereas the upper-priced Chinese one will last around 18 months for around $180. Your choice. I recently chose the latter - 150 ltr/min for $230 - and so far so good.

The Maxtracs are a good investment as a recovery mat - one of the few that work in both mud and sand.

Cheers,

Gordon


Cheers Gordon, that's the sort of specifics I was looking for.

I realise that you are in Perth and may not know where to buy here in Brisbane but can you make a compressor recommendation?

Also, what's your thoughts on the 'track' style anti-bogging device...the plastic mat things that you stick under your tyres?

Regards,

Kev

[Disco4SE]

Hi Greame, are you happy with the Pirelli ATR's? What are they like off road?
I supposed to be getting mine today
Cheers Craig

[Graeme]

The 19" Pirelli ATRs are wearing a lot faster than the 16" LT Pirelli ATRs that I had on my D2 and the outside voids are very shallow compared with the 16" too, presumeably a factor in their higher speed rating. No tyres wrecked after 15K with some daily fast gravel road use so they're doing the job for me.

[Graeme]

Good job you don't have a long straight drive way...:)
On that particular occasion not having to stop to open 3 gates would have been good, and saved quite a bit of fuel too. I went back and closed them all when the medical emergency turned-out to be a non-event.

[Disco4SE]

Hey Greame, what are the Pirelli's like off road????

[rmp]

Shifted all compressor talk here as per Gordon's suggestion:

http://www.aulro.com/afvb/d3-d4-rrs/106754-all-about-compressors.html

as many will have lost interest in this thread thinking all we're talking about is 19s and pedantry about 0-100 times when in fact it's much more exciting...

[sean c]

Hi guys,
New to forum. I have D4 3.0lt on order and tried to get the smaller brakes and wheels fitted but LR would not oblige. Have found this thread fascinating as I have been researching why I cannot have the smaller sized brakes. Some of the reasons I have been given by LR do not make sense to me. More power and torque and insurance and rego problems were quoted to me.
When I compare specs on the 2.7 lt model vs the 3.0 lt model I note that they both have exactly the same gross vehicle weight of 3,240 kg, top speed of 180kph on each and towing capacity the same.
My understanding is brakes should be designed for the vehicles maximum speed and weight. Acceleration and torque should be irrelevent if both vehicles are travelling at max of 180kph.
Australian Design Rules do allow modification of brakes and the application form asks about gross weight and maximum design speed. No mention of accelaration. Can't see how they couldn't approve the smaller brakes as the weights and speed are identical.
Any car that has ADR aproval can be registered. Not sure how insurance companies handle this but should be no different to any other authorised modification.
ComLaw Legislative Instruments - Vehicle Standard (Australian Design Rule 31/02 - Brake Systems for Passenger Cars) 2009 (ADR 31/02) (http://www.comlaw.gov.au/comlaw/Legislation/LegislativeInstrument1.nsf/0/60522FD078136A33CA2575DE00792C44?OpenDocument)

If anyone has done this modification please contact me as I am ineterested in any tecnical or other issues experienced.
My main reason for wanting to fit 17" wheels to the smaller brakes is availability of replacement tyres outside of capital cities and sidewall clearance when aired down.
sean

[Disco4SE]

Hi Sean, gghaggis is in the process of getting together an order for 18" specially made rims. He needs 15 sets for the company to produce them. So far he has 7 sets (including mine).
This way, you do not have to touch the brake arrangement. Sourcing 17" rims is impossible.
Should jump on the band wagon and put your hand up for the 18's
Cheers, Craig

[rmp]

Sean

Typically manufacturers and dealers will make anything up to make you go away. In some cases they may believe what they say and in some cases they may be correct.

The ADRs do permit brake changes and there are a series of tests to be performed which are easily passed by modern vehicles. You can try jumping those hoops, let us know how you get on.

If you really want 17s I'd change your order to a 2.7L. If you want the 3.0 then keep the 19s and get the best offroad rubber you can, then get out there and enjoy. The car will still go a lot of places even on 19" rubber. But don't take the stock tyres out too far in the bush.

And support GGH's initiative!!!

[CaverD3]

LR would not have approval for the import of 3.0L spec with the small er brakes. the range would be based in marketing not ADRs but they would need to get approval to supply you with a different spec. from LR head officeand DOTARS probably. Too much hassle for them really. But no reason why you can't change them depending on your state laws you may need an enginerrs approval though.

[scarry]

Just thought i would revive this thread with the following.Coopers are testing tyres in 18,20 & 22" rim size.The are very robust ,not quite an A/T.
Shame there appears to be no 19" in the line up at the moment.
The tyres are specifically for US spec D3/4,& RR which probably don't have 19" rims.

There is more on their web site.They may be available shortly.

Hope the above isnt a repeat of another post.

[Celtoid]

Hi All,

I recently posted a D4 Beachwork thread. On that I talked about an unplanned creek, wash-out incident. This is now an insurance claim as both front wheels were buckled and I want to get my D4 checked to ensure that there is no other damage.

I have to ask, after reading threads about the suitabilty or robustness of the standard Goodyear tyres, are there any genuine reports of rim-pinch or blow-outs etc?

I've had mine in gravel and rocks on several occasions and was surprised to note that there were no scollops taken out of them...in fact there was no damage at all.

During my washout experience, I hit a wet sandbank so hard that I've written off two wheels....yet the tyres...which were at low pressure for the beach, remained unscathed.

I realise that a more aggresive tread pattern would help in a lot of circumstances but are the tyres really so bad, inaffective?

Regards,

Kev.

[rmp]

Tyres are rubber so they bounce back into shape. You can have a flat and drive on it a short distance, reinflate and all's good. Rims...not so much. Tyres tend to suffer most from rips and sharp stuff, you don't find that in sand.

If the rims were both buckled I'd be most worried about the vehicle. Wheel alignment check would be a good place to start.

Aggressive patterns don't help in sand but do everywhere else except for bitumen.

[Celtoid]

Tyres are rubber so they bounce back into shape. You can have a flat and drive on it a short distance, reinflate and all's good. Rims...not so much. Tyres tend to suffer most from rips and sharp stuff, you don't find that in sand.

If the rims were both buckled I'd be most worried about the vehicle. Wheel alignment check would be a good place to start.

Aggressive patterns don't help in sand but do everywhere else except for bitumen.


Thanks Robert, working on getting everything checked underneath...shame LR weren't interested in helping. Sort of stupid as anything that gets missed now will probably bite them later on warranty :confused:.

I guess the point I'm making is the fact that the tyres took a really hard hit and didn't smash against the rims...thus causing a puncture. After the gravel work that I've done, still no tears or scollops either. Has anybody on this site reported destroying a standard 19" under non-crazy driving circumstances?

Regards,

Kev.

[CaverD3]

The 18 inch Wranglers on the D2 were poor with very week sidewalls. Mine were easily punctured by sharp gravel and I ripped one open oa curb. If the ones on the D4 are anything like it i would get something better.

[rmp]

Kev

I would be a bit cautious about drawing conclusions on the standard 19" front as I doubt there is much data for a statisically significant base. It is possible to shred even the toughest tyres, or by pure luck take say 21" roadies on a rough road and not damage them. Also, those that do go offroad will be swapping rubber. I've driven 19 roads offroad and had no issues, but a weekend doesn't prove much in the way of tyre longevtiy.

What I can definitely say is that any road tread/passenger construction tyre, and particuarly the higher-speed rated low profiles are not suitable for ongoing dirt road or offroad work.

The hit on the tyre wouldn't damage it anywhere near as much as a rip or tear. Offroad tyres have deep tread blocks (say 15-20mm) so if you rolled over a 14mm tall tack it wouldn't touch the carcass. Do the same with a road tyre and that same tack would go right through the blocks and penetrate the carcass. Also, the offroad tyre's carcass will be thicker and stronger.

Note that there is also a difference between the passenger/road tyres fitted to the likes of Japanese utes and the passenger/road tyres fitted to the 3.0 D4. You wouldn't want to run at high speed on the former for too long!

If you asked any experienced offroader what the four things to change on a stock vehicle are to make it into a tourer I can guarantee that most of them would put tyres high on their lists.

[scarry]

Thanks Robert, working on getting everything checked underneath...shame LR weren't interested in helping. Sort of stupid as anything that gets missed now will probably bite them later on warranty :confused:.

I guess the point I'm making is the fact that the tyres took a really hard hit and didn't smash against the rims...thus causing a puncture. After the gravel work that I've done, still no tears or scollops either. Has anybody on this site reported destroying a standard 19" under non-crazy driving circumstances?

Regards,

Kev.

Also,tyres can be damaged,some people call it "bruising",and may not show any sign of a problem,even if taken off the rim for a thorough inspection..A problem may occur later in the tyres life.
If it was my vehicle,i would push to have the front tyres replaced as well.

[Celtoid]

Kev

I would be a bit cautious about drawing conclusions on the standard 19" front as I doubt there is much data for a statisically significant base. It is possible to shred even the toughest tyres, or by pure luck take say 21" roadies on a rough road and not damage them. Also, those that do go offroad will be swapping rubber. I've driven 19 roads offroad and had no issues, but a weekend doesn't prove much in the way of tyre longevtiy.

What I can definitely say is that any road tread/passenger construction tyre, and particuarly the higher-speed rated low profiles are not suitable for ongoing dirt road or offroad work.

The hit on the tyre wouldn't damage it anywhere near as much as a rip or tear. Offroad tyres have deep tread blocks (say 15-20mm) so if you rolled over a 14mm tall tack it wouldn't touch the carcass. Do the same with a road tyre and that same tack would go right through the blocks and penetrate the carcass. Also, the offroad tyre's carcass will be thicker and stronger.

Note that there is also a difference between the passenger/road tyres fitted to the likes of Japanese utes and the passenger/road tyres fitted to the 3.0 D4. You wouldn't want to run at high speed on the former for too long!

If you asked any experienced offroader what the four things to change on a stock vehicle are to make it into a tourer I can guarantee that most of them would put tyres high on their lists.

All good points Robert, guess I'm thinking that as time goes by and there are more 19" rims on the road (as I hear the Japs are planning on a lot of 19" releases) that the manufacturers will cater for the need and make better, tougher tyres. Obviously the points you made regarding tread and sidewall thickness/toughness wil be an issue until this happens....better construction may...may....help.

Also I still don't think I'd be tackling anything too taxing in the tyres I currently have but when I fist started reading about them I expected to get a punture at the first rock I hit.....which certainly hasn't been the case at all.

Tread size and ballooning....well...who knows...LOL!!!

Thanks.

Kev.

[Celtoid]

Also,tyres can be damaged,some people call it "bruising",and may not show any sign of a problem,even if taken off the rim for a thorough inspection..A problem may occur later in the tyres life.
If it was my vehicle,i would push to have the front tyres replaced as well.

Good point Paul, I talked to the smash repair today and we discussed getting the tyres checked out too.....but like the 'undercarriage' of the car, it's hard to push the case when there are no obvious signs of damage.

The smash repair is going to send the car off to a suspension and steering specialist to get checked out, as I've really pushed that point....as now being paranoid, am feeling slight movement and looseness in the steering, etc....:(

Singularly disappointed in LR though. If I was LR, since the car is under warranty and the owner approached me....I'd jump at the chance to get EVERYTHING checked out...so that it didn't bite me in warranty claims later. But no....completely uninterested! Unbelievable!

:confused:

[Graeme]

... After the gravel work that I've done, still no tears or scollops either. Has anybody on this site reported destroying a standard 19" under non-crazy driving circumstances?
After hosing the built-up mud from my rear 19" rims yesterday, I found 1 rim has been seriously gouged by a rock yet the Pirelli ATR tyre is unmarked. The vehicle has not been "off road" although I do have 2 kms of sometimes mud-puddle driveway and 4km of gravel road before the bitumen. I'm still waiting for the 2.7 brake parts to arrive.

[Disco4SE]

So far, I have had 3 of my 19" rims re-done from scratches. One occasion was when I was bogged up against an embankment and the rims were spinning against it.
This is why I brought a set of second hand rims with MTR's.
Cheers, Craig

[gghaggis]

I've gouged two 19" rims and torn the sidewall of one MTR, rendering it unusable, hence my reason for selling the rest of mine and sticking with the 18" rims.

Cheers,

Gordon