275/55R20 KO2 or LTZ

[Graeme]

Is the advantage of a LT-rated carcase and more open tread pattern of the KO2 too compromised by the probable extra noise and fuel consumption compared with the LTZ?

[RR44TDV8]

Is the advantage of a LT-rated carcase and more open tread pattern of the KO2 too compromised by the probable extra noise and fuel consumption compared with the LTZ?
Graeme, if you are going with 275/55R20, and so you should, try the Pirelli scorpion ATR. I bought these hoping they would be quiet and they're great. I have had them on wet clay mine access roads and in U.S. Up to their armpits and they clean well and seem to find grip where they really shouldn't.
On road, they're brilliant, a little less quick to turn in and a little more prone to wander than the 255/50 but everything else is brilliant.
Feel free to drive mine if you want to try them out. I'm at Balgowlah, 10 minutes from Manly and about 20 minutes from your dealer.
Reds
Grant

[Graeme]

ATRs wouldn't be my first choice having tried them in 255/55R19 on my D4, although I did like their quietness and good steering which I suspect are at the other end of the scale compared with the KO2. I was initially impressed with the ATRs even in sloppy stuff but grew to mistrust them at speed in heavy rain so would try the LTZs instead if the KO2 seem too uncivilised.

Thanks for the offer to test drive although I don't think it would help with the tyre selection. The less direct steering of the size is not a concern as I have 265/65-17 on my D4 that seem fine. I'm looking for sidewall durability in rough going so the availability of the LT KO2 in this size is a significant attraction. However I don't want the noise of my LT 17" Duratracs for everyday driving, not that their noise was unduly intrusive on a recent 6,000 km outback trip.

The tyres on the vehicle will be serviceable for at least a couple of months. However the very short sidewalls are a liability on our gravel roads and the lack of tyre suspension for my wife's injured back coupled with the current availability of the KO2 means that a decision on more suitable tyres will be made sooner rather than later.

[RR44TDV8]

ATRs wouldn't be my first choice having tried them in 255/55R19 on my D4, although I did like their quietness and good steering which I suspect are at the other end of the scale compared with the KO2. I was initially impressed with the ATRs even in sloppy stuff but grew to mistrust them at speed in heavy rain so would try the LTZs instead if the KO2 seem too uncivilised.

Thanks for the offer to test drive although I don't think it would help with the tyre selection. The less direct steering of the size is not a concern as I have 265/65-17 on my D4 that seem fine. I'm looking for sidewall durability in rough going so the availability of the LT KO2 in this size is a significant attraction. However I don't want the noise of my LT 17" Duratracs for everyday driving, not that their noise was unduly intrusive on a recent 6,000 km outback trip.

The tyres on the vehicle will be serviceable for at least a couple of months. However the very short sidewalls are a liability on our gravel roads and the lack of tyre suspension for my wife's injured back coupled with the current availability of the KO2 means that a decision on more suitable tyres will be made sooner rather than later.

I heard so much about the "standing water" issue with the ATR's before I bought them but I have had no issues. They have been through really hard rain on the M1 at least a dozen times and I did a trip to Brisbane where it rained all the way there, the whole time I was there and all the way back. Never had a problem. I really love them and for the best part of their life so far, I owned a brace of tyre shops so could have changed them out at any time. Anyway, that's my view.
Reds
Grant

[Graeme]

Quite possibly I simply pushed the ATRs too hard.

[RR44TDV8]

Quite possibly I simply pushed the ATRs too hard.Graeme, don't think so.......I trawled the forums looking for answers when I first heard about this aqua planing thing and I did not find one post where an owner had had this experience in a Range Rover. Every post was about Disovery 3/4.
I am inclined to think it is a size/car thing. The disco wears it tyres in a completely different way to the Range Rover and I think the amount of contact patch on the ground with the 275/55R20 is the answer.
I think you will regret the L/T sidewall structure but perhaps not if you don't get used to a better riding tyre.
I listened to Chris with his Cooper purchase and very nearly went that way but I wanted the extra sidewall of the 275/55 and could not get something as quiet as I wanted with the A/T pattern I wanted. I have had Mickey Thompson which are from the same stable as Cooper and I used the new M/T AT3 which is a similar tyre to the cooper but I couldn't stand it. I had them in 265/75r17 on a Nissan navarra and also on a VW Amarok and the noise was something else. So bad that when I sold the Nissan, I had to put a set of b/stone tyres that we took off another car onto it so someone would buy it. The first two people who drove it with the M/T's thought the driveline was falling out! This put me off the coopers as I didn't want to suffer the noise when the tyres got to 15,000 - 20,000k's.
I know the Pirelli isn't a "full on" AT tyre but it suits me perfectly as 90% of my driving is on roads, maybe dirt or gravel or bitumen but roads.
I'd like to see your car one day so maybe when you get your tyres we can do some driving and compare?
Regards
Grant

[Graeme]

I wonder how many of the D3/D4 bad experiences were with vehicles fitted with e-diffs that may have adversely affected the steering in such conditions. I can feel my D4's e-diff keeping the vehicle straight if the throttle is opened a little whilst steering through slushy stuff on my driveway without TC having activated.

I am very mindful of only an extra 2+ cm sidewall height over the standard size so the extra load carrying ability of the BFGs vs the ATRs (LT @ LI 115 vs P @ 111) might be significantly detrimental to ride improvement. The LTZ @ 117 may be similar to the BFG. I'm a little wary of the longevity reports of LTZ's but am prepared to give them a try.

I wont have 2 sets of rims/tyres again so compromises will be made. ATRs and LTZ would probably be the sensible choices and more than adequate for the occasional rough use but the expected extra noise and poorer handling of the BFG is probably OK too. I may make a spur of the moment decision when provoked.

[Blade74]

I've been thinking about those KO2's as well.
Will be very interested in your thoughts if you do get them!

[Graeme]

I think that the KO2 would be the most suitable of what's available in this size if doing a lot of outback travel. However most travel will be on sealed country roads, some with lots of hours driving, so a less aggressive pattern would be better providing the tyre is strong enough for the infrequent remote area trip. Hence I'm including the Nittos again as I think they would be tamer than the KO2s, producing less noise and rolling resistance yet still satisfy the other requirements. However 5 might be hard to acquire as they seem to be sold in lots of 4 or occasionally 2.

[Blade74]

We are talking BFG All Terrain and not BFG MTR aren't we?
The grapplers look more aggressive than the BFG All Terrain KO2.
What about General Grabbers?
Or don't they do that profile of 55?

[Graeme]

Yes BFG AT KO2, the recent replacement with new compound and sightly different pattern for the age-old KO that was favoured by many but disliked by some, notably for lack of wet road adhesion as they harden with age. A family member has run them for close on 20 years on a Patrol that does lots of touring and gets close to 100K kms out of a set. Some D4 owners have them in either LT265/65-18 or LT285/60-18 and can't speak highly enough of them, with others waiting on the imminent release here of the LT265/60-18 KO2.

A brother recently fitted the Grapplers in 265/50-20 to his 3.6 RRS but hasn't driven it much since so hasn't yet formed much of an opinion of them.

I haven't spotted any GGs in this size.

[Blade74]

I have BFG AT's on my Defender.
They were on the car when I got it and I've done 50000kms.
Been pretty happy with them.
But yes It did take some time to get used to the car and the tires after coming out of a Disco 4.
I had to keep bigger distances from cars in front and get used to a feeling of brakes that weren't as good.
My Disco 4 had original Tyres and then I had Pirelli Scorpion ATR's which I really loved. Awesome tyre.
I'm just wanting to go something slightly more aggressive and macho looking.
Yeah I know it should be 100% about performance and road noise etc but sometimes it's also about the look. ;-)

[Graeme]

KO2s have been given the nod. They're considerably cheaper than the Nitto TG2 (I didn't want the cheaper original TG) and I became wary of possible tram-lining from the very square edges of the Nittos. I'm undecided whether to fit the 5th to the spare at this time, making the decision once I discover whether or not there is room to fit a wheel in the boot beside the fridge after having ruled-out any possibility of it fitting deflated in the spare wheel well.

[Blade74]

I wonder if the KO2 won't fit in the spare tire location in the boot?
Is it a diameter thing or a width thing that makes it too big?

[Graeme]

I'll temporarily remove the left side plastic floor support to get the wheel in (valve removed) to test whether the wheel will sit level and low enough. The plastic will be trimmed and spacer blocks fitted for the floor if necessary if the fit is acceptable. The overall well diameter is big enough but the step around the bottom may prevent the wheel sitting on the bottom. If the wheel is sufficiently centred the clamp may do the job but a longer bolt may also be required.

The spare will fit above the floor beside the fridge so all 5 tyres will be fitted to rims, but I'd be looking for another 20" rim to fit below the floor for local use to free the boot space. 1 original tyre is new whilst the other 4 are worn on the o/s edge.

[Graeme]

An unfitted LT275/55R20 BFG AT KO2 tyre fits in the spare wheel well if the left plastic support piece removed. The plastic will be trimmed back behind the metal only as necessary and leaving the original floor clip intact. Spacer blocks of about 50mm were needed on the bottom to keep the tyre level. A 20-40 mm aluminium RHS frame will be screwed to the underside of the floor edges to support the floor and to prevent items from disappearing into the well, with the thickness to be determined once a tyre is fitted to a rim. The floor will locate slightly towards the front of the vehicle to allow room for the flap at the base of the lower tailgate when the tailgate is closed.

https://www.aulro.com/afvb/images/imported/2015/08/375.jpg

https://www.aulro.com/afvb/images/imported/2015/08/376.jpg

https://www.aulro.com/afvb/images/imported/2015/08/377.jpg

[Graeme]

The BFGs are now fitted. LLAMS extra low whilst in access height mode appears to drop the vehicle to the bump-stops as the ride is very bouncy even when barely moving yet there is still plenty of clearance around the tyres to cater for compression of the bump-stops. The spare is fitted although additional dense sponge blocks for the tyre to rest on will be installed, along with a 50mm spacer of some description (perhaps very dense sponge or similar) around the floor edges.

This is normal height although not particularly informative at this angle.
https://www.aulro.com/afvb/images/imported/2015/08/269.jpg

https://www.aulro.com/afvb/images/imported/2016/03/254.jpg

[RR44TDV8]

Graeme, what about the noise........are they noisy?

Rgds
Grant

[Graeme]

They're dead quiet under the carport :D but should get some idea tomorrow.

Today I took particular note of the noise on coarse bitumen produced by the new Hankook RF10s on the D4 19" rims now removed to try to get a fair comparison. I would happily live with the Hankook's noise because of their great traction and steering in the sloppy conditions here at the moment. However I wasn't prepared to fork out significant money for a set of D4 19" rims as the 19" Hankook's carcase isn't known for its strength. I estimated the BFG sidewalls to be 8-10 mm thick when felt prior to fitting.

[Blade74]

I'm following with great interest.

[Graeme]

They certainly look the goods for some serious usage, yet don't really look oversized or aggressive like a mud tyre. The flat tread with square edges protects the almost vertical sidewalls well and the rims get protected too, even though the tyres don't have rim protectors. I'd have no hesitation in taking the rims and tyres on the harshest tracks I've encountered, with the Pedirka PAR probably the worst mostly for its large, sharp boulders.

[Blade74]

They look awesome Graeme!
I'm deciding whether to powder coat my rims black before fitting them.
Really interested in how you think they perform on road and off?

[Graeme]

I think they should be the toughest tyres in this size because of their LT rating coupled with their LI 115 and the thickness of the sidewalls.

They were noisier than the 19" Hankooks on course-stone bitumen and some minor noise on some very smooth bitumen, but harsh-riding. After letting the pressures down to 32/35 late morning after standing for a couple of hours the harshness had gone but the noise increased significantly to an unacceptable level. Hence I have some fiddling to do to sort out pressures.

[Graeme]

Really interested in how you think they perform on road and off?The RRV steers at 100 kph around bends with great composure without any hint of the tyres being other than high-speed on-road type. The steering and grip in the current sloppy track conditions (gravel road and hard dirt driveway when dry) is just as confidence-inspiring. These tyres are wide by my standard for gravel or muddy surfaces but don't seem adversely affected other than possible increased fuel consumption especially on unsealed surfaces at higher speeds, but the wide tread and upright sidewalls should be good for rocky terrain too. Its been a long time since I've seen tyres with this profile, with most these days having bulging sidewalls. I haven't yet let them down to soft sand pressures to see how well they elongate before the sidewalls bulge too much but with their larger diameter I think they will be quite OK. After-all, their sidewalls are the same height as 30" tyres on 18" rims but with the advantage of a shallower ramp angle in sand due to being almost 32" rather than 30" and about half an inch wider tread than standard tyres.

The ride quality and noise both seem acceptable today having raised the pressures by 2 psi for its normal almost empty state. I expect to have to increase rear pressures with extra load to maintain the noise/ride balance. I may still get to build a system to make the CVDs softer for slow bumpy travel (< 50 kph?) when the vehicle doesn't ride ruts and bumps as well as I think it could.

[Graeme]

I only spotted late today that the cargo area floor was still sitting up on the spare tyre leaving a gap all the way around letting in road noise from the rear tyres. The floor now sits on 40mm high x 50mm wide Ethafoam 220 strips on all sides with the fridge and toolbox providing some weight to keep it sealed. Maybe that will reduce the noise that's primarily at slower speeds that earlier today I assessed as mostly coming from the rear tyres. Perhaps a denser foam will be needed as Ethafoam 220 is marketed for its load carrying and shock absorption rather for its sound absorption but inexpensive to try.

[Blade74]

Interesting.
Is that with the tyre inflated?
Have you done any dynamat in the spare tyre well?

[Graeme]

The spare is totally deflated. No Dynamat is fitted so might get some.

[sandgroper57]

Looking to put some 275,s on my RRS, rims are 19" & 9" wide so 275 is just ok from a legality point. Currently has 255's.
Has anybody done this ? If so would appreciate any comments and what brand of tyre you have tried.


Cheers and thx

[Graeme]

You need to ask the question in the D3/D4/RRS section as the suspension and body of your vehicle is quite different to that of these L322 Range Rovers, so different limitations on tyre diameter and widths as well as the rim widths.

[rar110]

Graeme
if they fitted, would you nave gone with 18" rims (with an equally capable tyre) over the 20s?

Before the next big will need to decide on either 18s or 20s. Used 20" rims are a lot cheaper, and would allow me to have two sets of tyres (255/55/19s and either 285/50 or 275/55 on 20" rim).

Given you owned a D4 with 19s for a while, I assume you have asked yourself the same question.

thanks

[Graeme]

If I could have bought a set of D4 19" rims cheaply then I would have tried them with Hankooks. 18" are still a possibility but the 20" would have to be bad to warrant the investment in rims and new brakes too.

The large 20s adversely affect the gearing at 100 kph where the revs are just a little low with these vehicles' high ratio diffs when towing a trailer, but not enough to warrant a rim change. The extra 1" body height is proving a nuisance, having to drop to the bump-stops for my wife almost every time so I may have to get side-steps. I'll have to do something to lessen the reverberation from these tyres too - the noise is currently worse than the 17" Duratracs I had on the D4.

More tyre choices in 18" although probably still enough in oversize 20".

[Blade74]

Where are you at Graeme? I'd love to check out your car and see the Tyres.

[Graeme]

I'm at Marrar, half an hour north of Wagga, so not just 5 mins away.

[Graeme]

Where are you at Graeme? I'd love to check out your car and see the Tyres.
Are you contemplating going to the LR Expo at Camden? I'm considering a short visit as I have family in Camden and Narellan to see at the same time.

Edit: Most likely Saturday.

[Blade74]

Unfortunately I'll be away in the grampians rock climbing.
I'd love to go though.

[Graeme]

Today whilst fitting the Tow-Pro I found that there was still a half inch gap along the left side between the foam strip and the floor cover. The layer of thick carpet now glued to the underside of the foam strips seems to have closed the gap but I'll have to wait a day or 2 to discover if there's any improvement. Dynamat is yet to be fitted to the panels in the spare wheel well.

[Graeme]

Prompted by a remark on another forum, I realise that mine's spare wheel well floor is free to resonate whereas its normally damped by the spare wheel resting on and clamped to it, as my spare tyre only sits up on the edges. Its probably also why the engine noise from passed trucks is only heard as the front of the truck slips past the rear of the RR. Changes will be made!

[chaybra]

If I could have bought a set of D4 19" rims cheaply then I would have tried them with Hankooks. 18" are still a possibility but the 20" would have to be bad to warrant the investment in rims and new brakes too.

The large 20s adversely affect the gearing at 100 kph where the revs are just a little low with these vehicles' high ratio diffs when towing a trailer, but not enough to warrant a rim change. The extra 1" body height is proving a nuisance, having to drop to the bump-stops for my wife almost every time so I may have to get side-steps. I'll have to do something to lessen the reverberation from these tyres too - the noise is currently worse than the 17" Duratracs I had on the D4.

More tyre choices in 18" although probably still enough in oversize 20".


Did you want some ffrr 19"? I have 5 laying about

[Graeme]

Thanks for the offer. However having gone down the path of acquiring the 20" BFGs I will be persisting with trying to tame the noise they generate. Also, unless the rims are from a MY11/12 they supposedly don't fit over the 6-pot Brembo front brakes.

[Graeme]

It seems that I struck gold with fitting dampening material to the flat panels in and around the spare wheel well. However the front still needs attention so I'll start with a couple of areas visible under the bonnet although I suspect there will be other culprits that reverberate.

[Blade74]

Nice, I'm planning on some dampening material in mine soon.
What are the BFG's like for flicking rocks up?
I don't have any front mud flaps and wonder what the rocks flicked on the doors and sides will be like?

[Graeme]

I fitted front mud-flaps to reduce mud on the doors prior to fitting the BFGs which would now also be limiting stones. However I haven't particularly noticed the noise of flying stones when travelling my loose gravel lane at 100 kph. I might have to check the paintwork though.

[Graeme]

No obvious noise from flying stones on a quick run on loose gravel back-roads and lanes today, which this vehicle with its CVDs and these tyres handled superbly especially with a 30mm lift to keep away from the bump-stops. What a great combination!

[Graeme]

There is hope that the reverberation being experienced is temporary as the noise is confined to the driver's side. The nuts and screws holding the guard liner were loose, obviously not having been tightened properly after fitting the front mud-flaps. I should know if the reverberation/resonance has gone on the next outing.

[Graeme]

Unfortunately there was no improvement after tightening the guard liner nuts and screws. However I've just found an exhaust heat shield that runs along the inside of the sill immediately below the driver's seat that rattles and vibrates against the sill if flicked. Earlier today I wondered if the noise was coming from the bottom of the door or through the floor so hopefully this time I've found the culprit.

[Graeme]

Still no joy with stopping the noise. However I spotted that there is no bottom to the cavity below the brake booster other than the plastic guard liner whereas the passenger side has the large battery tray blocking most of the cavity. I'll stuff an old towel in there for a trial.

Oh yes, whilst checking the passenger side I found the battery positive cable that runs to the rear rubbing on a sharp metal edge due to the cable being incorrectly positioned - not good for the vehicle's longevity!

[Blade74]

Do you think the noise is a by product of the Tyres vibrating??

[Graeme]

Certainly caused by the tyres but seems not tyre on road noise but secondary acoustics, perhaps a panel vibrating or an echo.

[Blade74]

Ok thanks. I'm still thinking about putting these Tyres on mine in the next 6 months.
Definitely enjoy hearing how they go on yours.

[Graeme]

Another possible cause now crossed off the list as stuffing the void below the brake m/c & booster with towels achieved nothing. No noise or roughness from the wheel bearing either when turned by hand, not that the noise really resembles a noisy bearing. The hunt continues.

[Graeme]

Forever hopeful and clutching at straws I have now removed the very tinny-sounding gearbox shield. However during the process I discovered that the thin metal heat shield over the bottom o/s corner seam of the right foot-well area twanged when touched as it was just touching the seam joint. The gearbox shield will be refitted with a pad of sound deadening material after the next test but I'm pinning my hopes on the other shield which has now been moved away from the body seam.

[austeve01]

I wonder how many of the D3/D4 bad experiences were with vehicles fitted with e-diffs that may have adversely affected the steering in such conditions. I can feel my D4's e-diff keeping the vehicle straight if the throttle is opened a little whilst steering through slushy stuff on my driveway without TC having activated.

I am very mindful of only an extra 2+ cm sidewall height over the standard size so the extra load carrying ability of the BFGs vs the ATRs (LT @ LI 115 vs P @ 111) might be significantly detrimental to ride improvement. The LTZ @ 117 may be similar to the BFG. I'm a little wary of the longevity reports of LTZ's but am prepared to give them a try.

I wont have 2 sets of rims/tyres again so compromises will be made. ATRs and LTZ would probably be the sensible choices and more than adequate for the occasional rough use but the expected extra noise and poorer handling of the BFG is probably OK too. I may make a spur of the moment decision when provoked.


Hi Graeme.

I see you are already using LT275/55 r20's on your L322 tdv8. I went to purchase that size in LTZ's today but was told by the guys at Coopers that they will scrub in various positions. Needless to say I haven't purchased anything yet as I particularly wanted the 117 rating on the tyres that I eventually buy.

Can you tell me if you experience any scrubbing with that size tyre at all.

I also phoned our local BFG dealer and he said they don't have a listing for the 275/55/20. I'd be interested to know your supplier if that's ok.

Any info on any of the above queries would be greatly appreciated.

I have a 2008 L322 3.6 TDV8 with 20in rims.

Thanks
Steve

[Graeme]

Initially I didn't detect any rubbing but recently found that the bottom edge of the inner guard that bulges over the fuel filler pipe at the front of the RR wheel needed the standard fix of a screw to hold it against the layer over the filler pipe itself. I regularly drop mine to the bump-stops and occasionally have moved forwards in a straight line whilst down (the front tyres rub when turned much whilst right down) so may have rubbed then, but more likely just from significant compression over bumps. No audible rubbing occurs at access height on full lock. Other AULRO members have fitted 275/55R20 Pirelli ATR without any rubbing.

I bought the tyres through ebay from Cornells Tyres for $365 + frt but they currently only have 1 left. Tempe Tyres have them listed for $420 + frt. Both suppliers must have direct-imported. They were listed to be available though general tyre outlets late last year but obviously haven't arrived yet.

I'm still trying to find the source of resonance from the tyres that's heard from the driver's seat but not the passenger's. Until yesterday I thought it was coming through the front but no noise is heard when leaning forwards so must be from the rear. I have yet to revisit the rear for a reverberating panel. My hope is that the cabin acoustics are not incompatible with the noise frequency of these tyres. Light vibration from the blocks can be felt through the steering wheel at very slow speeds, ie when barely moving.

[Blade74]

What are they performing like in different conditions for grip? Are they ok on the Rd and in the wet?

[Blade74]

Also just referring back to the Pirelli scorpion ATRs.
I had some on my 2010 Disco 4 SE with an Ediff.
Never had an issue in the wet ever.
Although I only experienced their first half of wear before I sold it so I'm not sure what they're like when worn down lower in the wet.

[Graeme]

Grip in all conditions is fine for my driving which tends to be 100 kph everywhere its allowed.

[Graeme]

Whilst looking for a used 275/55R20 for a 2nd spare I encountered new Yokohama Geolandar AT/S in this size (XL, 117S). I had a good run from the AT/S in LT245/70R17 on the D4 so with the current 4 for the price of 3 offer (effectively $346 ea) I'm considering buying 4 mostly to store for 3 years until the noisy BFGs are worn-out. However its an expensive way to get a 2nd spare so I might do well to keep looking for a used tyre.

[Hammer H]

Whilst looking for a used 275/55R20 for a 2nd spare I encountered new Yokohama Geolandar AT/S in this size (XL, 117S). I had a good run from the AT/S in LT245/70R17 on the D4 so with the current 4 for the price of 3 offer (effectively $346 ea) I'm considering buying 4 mostly to store for 3 years until the noisy BFGs are worn-out. However its an expensive way to get a 2nd spare so I might do well to keep looking for a used tyre.

Are they that noisy? I was thinking the bfgs next. I have the latest bfg mud terrain's on my p38, there's noise and on some road surfaces a little louder than others but overall they bother me.

Paul

[rar110]

Are they that noisy? I was thinking the bfgs next. I have the latest bfg mud terrain's on my p38, there's noise and on some road surfaces a little louder than others but overall they bother me. Paul

Mate
A P38, your in deeper than I thought. 😀

[Graeme]

The noise is quite intrusive and significantly worse when I'm in the driver's seat than the passenger seat. From both seats the noise seems to be emanating from the driver's foot-well area for both myself and my son when swapping seats. I think the open space below the brake booster through to the ground below is a major contributor but stuffing the void with old towels makes no difference.

Edit: I have yet to fit the 2nd spare with its standard tyre to the front right for a noise test.

[Hammer H]

The noise is quite intrusive and significantly worse when I'm in the driver's seat than the passenger seat. From both seats the noise seems to be emanating from the driver's foot-well area for both myself and my son when swapping seats. I think the open space below the brake booster through to the ground below is a major contributor but stuffing the void with old towels makes no difference.

Graeme is this also the experience of others with the same tires? I thought the new bfg compound was meant to reduce noise. Which seems to be the case with the ko2s. My old man always said don't get mud terrains they are bloody noisy, but once he jumped in my p38 with them he was very surprised. Assuming this is the case with the compound and they are quieter I would have thought other all terrains would give the same problem. Particularly if it's just that location. In the car that's allowing the noise in.

Cheers Paul

[Hammer H]

Mate
A P38, your in deeper than I thought. 😀

Yes one for all seasons. Well two seasons. I think with a Range Rover and for those who do their own repairs a second transport option is required. I'm still waiting on a call back from Mr McGoo for advice on what to do if both break down.

[Graeme]

The noise seems only from the front right and as it doesn't change frequency with speed it must be a reverberation. There's also a lot of road noise on fast gravel. The noise from the front passenger seat position is only minimal. The battery on the left side might be preventing reverberation and though I cannot see what's below it, I would expect it to have the same opening to the ground as the right side.

Initially there was bad noise from the rear when the floor, raised on full-length sponge blocks because the spare doesn't sit on the bottom of the well, allowed the well's side and floor panels to reverberate. However since sound-deadening material was affixed to those panels the reverberation no longer occurs. Its possible that the noise is still coming from the rear so if the standard tyre on the front doesn't cure it then it will be put as the spare and the floor returned to normal for a test.

People have recently fitted large 18" KO2s to D4s yet I haven't seen any reports of intrusive noise. However reports from the US suggest that the KO2 is not as quiet as promoted by BFG.

[Blade74]

Graeme can you get some dynamat into that area below the brake booster?

[Graeme]

So far I've only applied a small piece to the vertical side panel right at the top but I'll have to see if I can get some further down.

I've just discovered that the driver's side plastic sill cover rattles significantly when tapped whereas the passenger side does not, so that will be fixed before trying anything else.

Edit: Padded material is already affixed to the firewall around the brake m/c so would have to remove it to fit dynamat behind.

[Graeme]

Perhaps still clutching at straws, but I found the heat shield above the catalytic converter clanged solidly against a body rail if even quite gently bumped, which might be the cause of the reverberation. This is the worst heat shield clang that I've found so far and being very solid against the rail below the floor, it was a promising find.

Having decided that the plastic sill cover couldn't possibly cause that much noise I removed the heat shield from above the right ARB mount and rear wishbone bush to try to improve its "deadness" but on checking around the area discovered the catalytic converter heat shield's clang. The bush shield was also improved by giving it clearance above the ARB and its bush bracket rather than resting on them. Fingers are crossed - again.

[Blade74]

It sounds like you could write an article about the L322 called - "all things that go clang"

[Graeme]

Perhaps, but then none were the cause of the noise.

Other things to try...swap wheels/tyres around and stuff the open-ended box section below the floor with old rags.

[Graeme]

Having swapped the RF & RR and the LF with the unused spare wheels and ensured that the floor of the spare wheel well cannot vibrate, I'm now considering the sill channels because they resonate when tapped with fingers. They are made of thin metal where not double-layered and are coated eternally with a thin layer of sprayed-on deadener, so presumably a concern even with road tyres. I thought about filling them with expanding foam but that would create a haven for rust, as would spray-on deadener on the insides so will look at what else might be possible, even as a temporary fix to prove or disprove the idea. Lengths of 6mm thick rubber attached with construction adhesive might be worth a try unless someone has a better idea.

[Graeme]

The latest theory is a noisy FR wheel bearing so a new one will be fitted. It would be unusual with only 30K kms but if the vehicle had done 100K I wouldn't hesitate to blame the bearing. The noise is only from the FR corner and can even be heard at 50 kph on a gravel road with a rattly trailer in tow.

[Blade74]

Hello Graeme, how did you go with getting that wheel bearing replaced?
Also how well do you think the All terrains protect the edge of the rims?
Do they stick out a bit from the edge of the rim?

[Graeme]

The bearing is booked to be replaced Tuesday after an aborted attempt by me at Easter due to lack of appropriate tools, which I now have made/purchased but giving the job to the local mechanic anyway. The noise has been getting worse and now could not possibly be blamed on tyres.

The tread-like upper sidewall layer extends to around half the sidewall height thereby giving some protection to the minimal bulge, which is 10mm further out than the rim edge. My rims' spokes curve outwards between the rim edge and the centre resulting in only 7mm protection at their maximum curvature - enough for flying stones.

[BobD]

My K02's are very quiet on the D4. Significantly quieter than the worn D697's. I was a bit worried after your posts of all the noise problems but I am very happy with the ride and the quietness. I think they are a bit stiffer in the sidewall than the D697's and the car handles a bit better, with a tighter feel and less moving around on the road. I am running the same pressures, 36 front and 42 rear most of the time.

[Blade74]

Thanks Graeme, I hope the bearing does the trick.
I find original size tyres don't offer much protection for the original rims.
I'm thinking of getting them repaired and painted before putting the AT KO2s on.

[Graeme]

Hmm, this morning a rear tyre was pinched against the rim hard enough to leave a nice black mark. A narrow rut in my driveway is normally straddled but my attention was elsewhere so the rear wheel found the rut resulting in an almighty bang from the left rear suspension. Time will tell if these sidewalls will survive as I did not expect the tyre to deform so readily.

[BobD]

Hmm, this morning a rear tyre was pinched against the rim hard enough to leave a nice black mark.


At least you didn't do what I did and take out a chunk of rubber and rim as posted in the D4 section. Mine was also pinched against the rim on a rock but I had about 16 psi in the tyre coming off a soft beach. I replaced my 500 km old tyre but the sidewalls are very thick and there was no damage inside and no belts visible under the flap of rubber. I will probably use it for a spare when I get around to putting it on a rim.

[Graeme]

No visible damage but cords could be fractured so I'll have to monitor it, but not in the same league as slicing chunks out of the sidewall.

[Graeme]

Unfortunately replacing the FR wheel bearing made no difference so I'm back to looking for an un-dampened resonating panel, similar to how the spare wheel well floor was. I've not previously considered the disc stone/dust shield which although doesn't have the typical rattle when one of the bolt holes has cracked, does vibrate to some extent when flicked and it also sounds slightly different to the left one. Hence it will get a patch of sound deadening material.

Edit: No, not the shields.

[Blade74]

How well balanced are the wheels? I know some tyres are near impossible to balance.

[Graeme]

No problem balancing these tyres on these rims, perhaps due to the relatively short sidewalls for the rim diameter, unlike 32" tyres on 16" rims.

[Graeme]

The reverberation cause has been resolved. The set of 4 brake pipes attached to the ABS modulator has 2 spacer clips, 1 not far from the modulator and the other out of sight down inside the cavity. The clip in the cavity was only attached to 1 pipe which allowed the pipes to rub together, which along with the very flexible modulator mounts allowed the modulator to rattle the pipes.

I still have to find the source of the front suspension rattle which occurs when slowly moving forwards or backwards over bumps and still can be heard at speed on gravel or our local sealed roads. The sub-frame bushes in the rear/upper arm obviously have been hitting their internal bump-stops but as the rattle also occurs in reverse, I suspect the bush is not the culprit.

[Blade74]

Hello Graeme. How are those tyres holding up? I just blew out a front tyre tonight along the M5 when I hit a random object with my front right tyre. So it's time for me to buy a new set of tyres now. The rears are both on they last legs. Im thinking BFG AT KO2 or General Grabbers if they make the right size.

[Graeme]

The KO2s are going fine, albeit with a little more noise on some surfaces than I'd like. Traction is never a problem either on wet bitumen at speed or sneaking through sometimes deep muddy slops trying to minimise road damage to lessen the risk of getting bogged on later passes.

112172

[Blade74]

Thanks mate.
I also like the look and specs of the Yokohama Geolander G012 in the same size.

[Graeme]

I had and liked the Geolander G012 in 17" on the D4 and having discovered them in this size with LI 117 since getting the BFGs and wanting less noise, I'm leaning towards the Geos for the next set. One of the reasons for fitting the e-diff is to remove some of the reliance on more open tread patterns. I really like the BFG performance in sloppy stuff but not the noise. I have enough problems hearing without adding to the not-so-background noise. A draw-back with the Geos is their narrower tread exposing the sidewalls to rocks, although I haven't seen a 275/55R20.

[geebs22]

Hi Grant.
I am looking for some new rubber for my '12 RRS and do about 90% on road (suburban driving, and highway towing a 2 t caravan. Don't want true off-road like the KO2 so interested in your comments on the ATRs.
So in your opinion the better choice is the ATR's?

Thanks
Graeme

[Graeme]

275/55R20 are too big for pre-MY14 RRS regardless of brand.

[BobD]

Graeme, your FFRR must be much more noisy than the D4! I can barely hear anything different with my K02's and there is no annoying noise, anymore than I had with D697's or Continental Cross Contacts before them. Mine even have a couple of pretty large rock chips from the Bungle Bungles track and Birdsville Track, which haven't made any difference to the noise.


I find the handling better than any other tyre I've used on the D4 and no noticeable increase in harshness, so apart from the high cost, I am very pleased.

[Graeme]

The RRV's noise apart from these tyres is virtually non-existent but my hearing could be unusually sensitive to resonating tyre noises. I also suspect that although these vehicles are very will insulated from drive-by noises from other vehicles, tyre on road noise hasn't been addressed sufficiently because the vehicles aren't expected to be fitted with aggressive tyres.

[RR44TDV8]

Hi Grant.
I am looking for some new rubber for my '12 RRS and do about 90% on road (suburban driving, and highway towing a 2 t caravan. Don't want true off-road like the KO2 so interested in your comments on the ATRs.
So in your opinion the better choice is the ATR's?

Thanks
Graeme
Hi Graeme, yes is my short answer. I have found the ATR's to be great in all conditions and I really like them! I would defer to other Graeme in regards to RRS fitment though as I am unsure about this.
Rgds
Grant

[Blade74]

So Tempe can do the KO2's fitted for $399 each.
I think that's pretty good. I might just do 4 for now and if I plan to do any outback trips swap the spare later.

[scarry]

So Tempe can do the KO2's fitted for $399 each.
I think that's pretty good. I might just do 4 for now and if I plan to do any outback trips swap the spare later.

What size?

Seems a very good price,where from?

I have been putting off getting some for ages,either 17's or 18's,as i have both rim sizes.

[Blade74]

20" size but I'm sure they'd have smaller sizes and possibly cheaper.
Tempe Tyres in Sydney.

[Blade74]

So I just got the BFG AT KO2's fitted in 20 55 275.
They're not too noisy so far.
There's definitely a bit of tyre scrubbing in the front guards at normal height at full lock on the frontside of the tyre.
Nothing drastic.
The rear right tyre rubs on some plastic when the rear of the car drops on acceleration or over bumps. I think it's just cosmetic.



112508

[Blade74]

112510

[Blade74]

This is the rear rubbing spot looking upwards from below.



112511

[Graeme]

The right rear needs a self-tapper near the bottom to hold the liner against the protection layer over the fuel filler pipe to prevent the tyre from rubbing through the liner.

[Graeme]

A passer-by in Canberra gave my tyres the thumbs-up yesterday as he walked past my not so clean vehicle. If I hadn't given the pressure cleaner a good work-out on the rims, under the guards, the windows and bodywork including the roof before leaving he'd have really had something to look at. The mud from my lane filled the gap between the tyres and guards behind the wheels. These tyres certainly like to pick up mud.

[chaybra]

get yourself a heat gun, apply heat and with a block of wood or someting, press in the bulge to clear the tire. thats how i got mine to clear.

[chaybra]

The right rear needs a self-tapper near the bottom to hold the liner against the protection layer over the fuel filler pipe to prevent the tyre from rubbing through the liner.


I wouldnt recommend drilling through the filler pipe in the process.....

[Graeme]

I was careful but better if the screw wasn't there to fall out so will try the heat-gun trick.

[Graeme]

Whilst the original bad resonance was resolved by refitting the brake-line spacer to keep the pipes apart, there's been a continuing light howl from very low speeds up to and including 100 kph on any surface, but non-existent at 110. After a 4 hr trip this morning I was moved to fit sound deadening to the inside of the RF guard and to the hollow panel behind it, as the front guards resonate when tapped whereas the doors do not. With the bonnet up and one hand along the top edge of the guard between bolts, the guard edge vibrated when the flat of the guard was tapped. It may be a day or 2 before a proper test is done to learn if there's any improvement. Forever hopeful!

Edit: Although only a test distance of 4 kms of sealed surface, the noise now sounds to be coming from the left front of the cabin whereas previously it was predominately from my right but also from somewhere else in the cabin. The left front guard is next!

Another edit: Even more promising was finding that the body box section that runs along the top of the guard and to which the guard mounts, when tapped with fingers, resonates like a drum at about the same frequency as that of the noise that has been driving me to distraction. I had applied deadening material to the right side's box section but covered the left one as much as possible, as well as with the guard itself. I'll find out tomorrow the success or otherwise of the exercise.

[Graeme]

In my final attempt to reduce the cabin noise from these tyres, the inner sides of the main front to rear rails have now been treated with patches of vibration damping mat as their several sections resonated at different frequencies when tapped. The outer sides and half the bottom was treated at build time with a spray-on material, but not the inner sides. On the left side some adjoining resonating panels below the floor were also treated but the equivalent floor panels on the right could not be done due to the need to drop the exhaust system to totally remove the heat shield to gain access above the right catalytic converter. However one 30cm long section of under-floor panel readily rattled/vibrated when poked with a long screw-driver, suggesting that the opposite, hidden edge missed being welded during assembly. That panel has now been sufficiently distorted to stop it rattling by jacking the screw-driver.

Tomorrow I'll find out if this last attempt has succeeded.

120523

[Blade74]

What is everyone using for tyres now?
Anyone using a good ATR that handles better than the KO2 on the Rd?
Maybe Pirelli Scorpion ATRs?

[Graeme]

Whilst I have no complaints with the KO2 handling on any surface, I have a set of Pirelli All Terrain Plus that will be fitted early next year. The AT+ tread is as open as the KO2, is as wide for sidewall protection, has almost the same load rating (113 vs 115) and importantly for me is reportedly almost HT quietness on sealed roads. However it is a passenger tyre rather than LT which is expected to provide a less harsh ride and hopefully will be strong enough. The sidewalls aren't as thick as the KO2s but are quite substantial for a P-rated tyre.

[Blade74]

Whilst I have no complaints with the KO2 handling on any surface, I have a set of Pirelli All Terrain Plus that will be fitted early next year. The AT+ tread is as open as the KO2, is as wide for sidewall protection, has almost the same load rating (113 vs 115) and importantly for me is reportedly almost HT quietness on sealed roads. However it is a passenger tyre rather than LT which is expected to provide a less harsh ride and hopefully will be strong enough. The sidewalls aren't as thick as the KO2s but are quite substantial for a P-rated tyre.

Thanks Graeme,
Are those AT+ readily available here in Australia?

[Blade74]

Ok I just found them online. 275/55R20 113T.
Does anyone know how they compare for actual size compared to the KO2?
Assuming similar rub.

[Graeme]

Here's a pic of the 2. I'll be keeping the 2 half-worn KO2 as spares.
The 1st AU shipment arrived a few weeks ago so I grabbed 4 in case none in stock when I needed them.

[Blade74]

Cool.
I’m curious how much quieter they are on bitumen and if they have better road handling than the KO2’s

[Blade74]

I’m also thinking of just going back to road tyres for a set.
Maybe the Michelin Latitude Sport 3’s
Haven’t been doing much offroading

[Graeme]

Mine temporarily has rather worn 19" Dynapro ATMs which slip everywhere in the slightest mud but the KO2s will be refitted this w/e.

[Blade74]

How come you changed Graeme?

[Graeme]

Balance issues firstly at a tyre shop (3 visits) then the local garage so fitted my son's 19" D4 rims waiting for the local garage to get their rarely used m/c off a pallet and bolted to the floor. Today I spent 2 hours setting-up the wheels properly on the m/c and balancing them myself, checking that the previous inconsistencies at both places had been overcome. They're now 0-0 regardless of their position on the m/c so hopefully they will now be good.

[Graeme]

The persisting apparent balance issue is likely caused by a loose (RH) lower arm ball-joint, a known sensitivity with these vehicles with 20" rims and standard size tyres due to the servotronic valve in the rack, expecting more so with over-size and heavy LT tyres. The ball-joint may have been damaged during the wheel bearing replacement some time ago as I recall the mechanic commenting on the trouble releasing it and the obvious sledge-hammer use on the hub suggesting rough treatment.

[Graeme]

To close-out my experience with the KO2 in LT275/55R20, unbeknown to me so far 2 of the now removed tyres have splits around the upper sidewall on 1 side of each tyre and both of these tyres had developed quite an alarming hole in the tread near the edge on the side where the splits occurred, presumably from splits having opened-up. I have yet to check the other 3 tyres for splits although none have holes in their treads.