V8 or TD5

[Koen]

Hi all,

Atm I have a disco 2 V8 from 2000 with 110k on the clock. I fitted it out to go travel around Australia (see picture)

Since the fuel economy is not that great on the V8 I'm considering buying a standard TD5 and swap suspension, tyres, rack, rocksliders,... from my V8 to the TD5 (03-04 model) and sell the V8 standard.

My question is, is it worth it to buy a TD5 with probably more km's then my V8 now has and built everything over? I know I will loose money on the swap, but might save it in fuel after a while, I'm probably gonna do a lot of km's the upcoming half year.


Thanks, Koen

https://www.aulro.com/afvb/images/imported/2016/06/7.jpg

https://www.aulro.com/afvb/images/imported/2016/06/8.jpg

[Roverlord off road spares]

But factor in higher repair costs, TD5 seem to do harmonic balancers more than V8s, fuel pumps, injector looms, plus servicing costs;)

[MR LR]

The V8 is cheaper to own these days.

Td5 repair costs are too high. And to get decent performance the economy isn't all that great.

[Pinelli]

My TD5 is getting up to 300kk, and fuel efficiency, while probably better than the V8, is really not brilliant either at 12-13L/100km (fair bit of city driving with that). I've decided recently that if it fell over (for whatever reason) I'd probably get a V8 instead.

Do the calcs. If the difference is 5L/100km, if you're doing 20,000km a year, the difference is maybe $1200 a year. It's going to take you a few years to recoup your costs, even if nothing goes seriously wrong.


But, if you're serious, I'd be happy to talk about swapping rigs :p

[697-Nodad]

Whats a bog standard pre update V8 worth $6k??

Double that for a good update TD5.

IMO keep the V8. The saved $6000 will buy a lot of jerry cans, and you'll have a
drive train / vehicle you know and trust.

I've just bought an update TD5...... I'm not going anywhere remote until I understand it totally. I had an old 93 S1 V8 and trusted that to go anywhere, only because I had the hours on it and knew every small fault etc. All i'm trying to say is even if your car is an old piece of ****, as long as you know why its crap... that's all that really matters.

knowing the car is all.

[PhilipA]

Not another thread that may hopefully not degenerate into a slanging match. LOL
IMHO it is personal preference
After 3 RRCs with V8s and never having owned a dieselI thought I would try a diesel that I had heard so much about, and now I don't think I would go back to V8.

The thing that amazed me was even with my stock TD5 pulling my 1tonne camper, it climbed hills far better than my extremely modifed for torque RRC. ( 3.9, sports exhaust, Unichip, Thor manifold, Bosch Gen 111 injectors etc with 50% more torque at 1600RPM)

I think for towing it is no contest TD5 every time , but if you plan to travel light then a V8 will be OK.
I personally find that the larger V8s are fragile, with cams wearing, head gaskets leaking and the possibility of sleeve slippage. I know V8s very well as I have pulled them apart often.
So far no problems with the TD5 but I have left it stock. I have asked the question several times on this forum whether chipping really does any good when you are towing, as it is ultimately the EGT which determines how fast you can go up a big hill towing. I prefer not to have to drive by an EGT gauge. Overtaking I guess is another thing but I have found no problems in that regard.
The fuel savings going about 18,000 Km around Australia were I estimate about $1600 or more as I could get fuel where it is cheap say Port Hedland instead of a roadhouse, the difference sometimes being 50cents a litre..

The other thing is that the range of the diesel is far greater, so I got across the Nullabor with a tank and 2 jerries with some side trips.

So I guess it depends whether you like Vroom vroom or rattle rattle, but it will take a long time to justify a diesel on fuel savings alone.
Regards Philip A

[Bytemrk]

Koen,

I did the same thing near 10 years ago, switched from a 2000 V8 to a 2003 TD5 which I chipped immediately as my right foot couldn't live with a standard TD5.

While I still think I did the right thing, I did own the TD5 for about 8 years and over 200,000Km.

The guys have a fair point that you will need to own it a while before you recoup the cost of change over.

However - as you say you are planning lots of Km's in the coming 1/2 year.... where you are planning on going may be relevant. For remote travel, the longer range is a plus - and everywhere out there has diesel - not everywhere has petrol.

Good luck with the choice....

[rangieman]

Not another thread that may hopefully not degenerate into a slanging match. LOL
IMHO it is personal preference
After 3 RRCs with V8s and never having owned a dieselI thought I would try a diesel that I had heard so much about, and now I don't think I would go back to V8.

The thing that amazed me was even with my stock TD5 pulling my 1tonne camper, it climbed hills far better than my extremely modifed for torque RRC. ( 3.9, sports exhaust, Unichip, Thor manifold, Bosch Gen 111 injectors etc with 50% more torque at 1600RPM)

I think for towing it is no contest TD5 every time , but if you plan to travel light then a V8 will be OK.
I personally find that the larger V8s are fragile, with cams wearing, head gaskets leaking and the possibility of sleeve slippage. I know V8s very well as I have pulled them apart often.
So far no problems with the TD5 but I have left it stock. I have asked the question several times on this forum whether chipping really does any good when you are towing, as it is ultimately the EGT which determines how fast you can go up a big hill towing. I prefer not to have to drive by an EGT gauge. Overtaking I guess is another thing but I have found no problems in that regard.
The fuel savings going about 18,000 Km around Australia were I estimate about $1600 or more as I could get fuel where it is cheap say Port Hedland instead of a roadhouse, the difference sometimes being 50cents a litre..

The other thing is that the range of the diesel is far greater, so I got across the Nullabor with a tank and 2 jerries with some side trips.

So I guess it depends whether you like Vroom vroom or rattle rattle, but it will take a long time to justify a diesel on fuel savings alone.
Regards Philip A
Lets hope it does not sink to another low:cool:
It is a personal choice and you will get the horror stories from both sides:angel:
My opinion is the Td5 and i have owned a couple of RRC v8`s standard and modified .
Go the diesel not all Td5`s do harmonic balancers and the service cost is not going to be the game changer in my opinion :D
I have owned 2 Td5`s and id buy another in a heart beat over the V8:cool:
This is totaly my opinion:angel:

[Rok_Dr]

Having traversed a similar path to PhilipA I have to agree with everything he says, the TD5 is far better for towing and you'll get further on a tank. Likewise I'm more than happy with the performance of the standard tune engine and pulling a 1.8 tonne van.

But given the work you have put into your existing car and the kms it has travelled I'd keep it and buy a few Jerry cans.......Or fit a long range tank if you haven't already done so. So I'm also in agreement with 697NoDad.

Cheers

Steve

[strangy]

if starting from scratch, I'd be going TD5 without hesitation.
Discussion on the merits of either relates to the above.
However in your case, assuming he vehicle is well sorted, I'd keep the V8.
The cost directly and in man hrs, buys a lot of fuel.

[ozscott]

What a great thread with balanced responses.

If I was doing it again I would consider a TD5 purely and only from the point of view of range. Having said that I would not give up my 4.6 D2 manual for anything - now that is torque with the Thor manifold, Bosch injection, high compression and exhaust work. Mine runs at 85 degrees C most of the time, so I avoid the risks with overhot running, and the 4.6 was typically the thickest casting. My 4.0 was excellent though and I would run it again. I think overall there is less to go wrong on a well maintained V8 (including WELL maintained cooling system) versus the TD5 but that would not stop me owning a TD5.

Personally I love how quiet and throaty the V8 is. For long range touring you cannot beat the TD5 in terms of range and ability to pick up diesel anywhere etc (although these days petrol is available even on outback properties). Personally I think overall the extra servicing costs of the TD5 compared to a V8 that has not been overheated (and has a well maintained cooling system) versus savings on fuel is just not worth it.

The off idle torque from the V8 is also a boon offroad.

If I didn't have a D2 and was going to set one up for a LOT of long distance remote touring I would go TD5. However given that my D2 is my daily driver and tows a 2 tonn boat and also does the odd long distance remote trip the V8 suits me better.

So it all comes down to what you value, what you like driving, and cost.

Cheers

[Pinelli]

Having traversed a similar path to PhilipA I have to agree with everything he says, the TD5 is far better for towing and you'll get further on a tank. Likewise I'm more than happy with the performance of the standard tune engine and pulling a 1.8 tonne van.

Steve

Now, can I ask about the towing thing? On paper, the V8 has better power and torque than the TD5. So why is the TD5 better for towing? Is it just the fuel, or is there something else I'm missing?

[rar110]

I don't own a petrol V8.

Given you know the car, the low kms, it's set up, it's a no brainer. Stay with the v8. You will pay a lot of money for an equivalent Td5.

[PhilipA]

Now, can I ask about the towing thing? On paper, the V8 has better power and torque than the TD5. So why is the TD5 better for towing? Is it just the fuel, or is there something else I'm missing?What is important to me anyway is holding speed on long hills on the highway.
The TD5 makes more torque than a v8 at about 2000-2200 RPM which is around the 100-110Kmh on the highway in locked top.

Now the result of this is that if you hit the enormous hill north of Buledelah going southbound you start at the bottom at 110Kmh and you are still doing 100 or so in locked top at the top of the hill towing 1000Kg.

My V8, even though tuned for torque was doing less than 100Kmh (maybe 90) and had changed back to third by the top and revving its head off.

To be fair if you get thwarted by some goose at the bottom of a hill in a TD5 you cannot regain speed up the hill as you don't have the revs to accelerate,vs the V8 where you can accelerate strongly by giving her the berries.
But it is far more prevalent that the TD5 will sail up the hills that the V8 will struggle on.
That is also a reason that I always discourage people putting hot cams in V8s.


Regards Philip A
I did all the mods on the V8 as I got sick of passing people on the flat only to be passed up the hills then having to pass again and so on. It helped a lot and a Thor D2 is maybe better than a RRC but still diesel is the Go and doing say 12L per 100Km vs the V8 doing about 16-17lper 100Km ( after mods and O2 sensors)..

[Pedro_The_Swift]

I followed all the work you did on yours Phillip,,
but as you know, at 2200rpm the V8 would be making around 95% of its max torque,, which will still be more than the max put out by the TD5,, and torques are torques,, whether diesel, steam or LPG, if the weights, gear ratios, and speeds are the same, up that hill, the car with the most torques will win,,
my green cars 4L was a beauty,, but this silver one was useless. bought at roughly the came kays too,,

I remember testing a brand new TD5 when I had my 3door,, and remember keeping my 3 door,,;):D

[Rok_Dr]

In my case the comparison was between a bog standard 94 soft dash classic and a 03 td5 auto. The 3.9l V8's torque is 314nm at 3100rpm, while the td5 auto is 340nm at 1950 rpm. More torque lower down makes all the difference. Plus 15l/100km vs 25l/100km towing in the V8 was a no brainer. The d2 auto also has lock up on 3rd and 4th as well.

That said the std v8 d2 is 340nm at 2600rpm so the difference between it and the td5 would be a lot less.

Cheers
Steve

[PhilipA]

That said the std v8 d2 is 340nm at 2600rpm so the difference between it and the td5 would be a lot less.

Weeell, my 3.9 really mirrored a Thor and I believe I had MORE torque at 2600 than a Thor , and I have to say that the torque RISE to 2600 is an issue.

On the open road in top locked you are never doing 2600 unless you are going very fast. Remember V8s are artificially restricted at low revs because of the need to limit NOx, thus all the criticism of engines like Gen111 of poor low down torque.

The old TD5 has its shoulder well into the torque curve at 2000 and the turbo is pushing hard . You are over the curve so shouldering back into the Max torque at 1950RPM.

I have to say they are like chalk and cheese, and I was amazed the first time I sailed over that hill. At the time I thought why did I waste my time and effort of many years on the V8.

Always the caveat that if you are baulked at the bottom it is a sloow trip to the top . When I am going up the Hume ( from Sydney to Canberra) I am always planning for the next bigun by ensuring if possible that I am clear of trucks and caravans at the start of the climbs.
Regards Philip A

[ozscott]

Of course you can always go the 4.6... Cheers

[Pinelli]

Thanks Gents,
And yes, a larger V8, say a Disco 3, is an option for the next rig. Although they seem pretty rare compared to the 4L 6 petrol model.

[ozscott]

The 4.0 is getting 300nm by 2000 rpm (Max still to come) and the 4.6 has 407 nm at 2600. Can't readily see a torque curve for the Thor 4.6 high comp but it must be around 360 or so at 2000 rpm. At the same revs the TD5 has 300nm...At 100 kph the D2 would be sitting on about 2200 or so. So about 380 or so for the 4.6 Thor and building when the TD5 is falling off. The 4.0 is good for towing but the 4.6 Thor is awesome. In terms of getting caught on Hills or overtaking think too the TD5 has about 60kw at 2600 and falling torque curve and the 4.6 is maxing torque and power is at 166 kW at that point which really is an extraordinary difference. The Thor manifold and Bosch Motronic did wonders for tractable towing. My advice is go a 4.6 conversion and love the grunt and sound. Cheers

[ozscott]

As a matter of interest I just did some highway work with GVM - driver, 4 passengers, utterly loaded for camping (literally every space in the rear (with steel cage) full to the roof including fridge, LPG bottles, AGM battery etc and 2 steel frame Coleman instant up touring tents on the roof alongwith camping chairs (huge wind resistance). I have a steel bullbar and sliders, alloy roof rack, and a fair bit of extra stuff. Recorded on fill up bang on 14 litres per 100k, doing 110 most of the time and a high climb up a range. Now doing 90kph constant that would drop to about 12.5-13 l per 100k with that load - wind resistance is a big factor at the speed I was doing. My truck has a 2 inch lift also which effects economy as does the 31 inch light truck tyres with greater footprint and (and much greater) weight than stockers.

Offroad doing low range 1-2 gear for several hours and climbing to 3000 feet and back (and again fully laden per the above list) - 22l per 100k. Kind of funny because even at this most unecocomical of travelling speeds it is still chewing less than a 100 series LC petrol tooling about town...

Not bad from a 4.6 V8 with that load.

Cheers

[Koen]

So different options what I can do apparently, doesn't make it easier for me though. :p

What concerns me the most is the range, that is way to low at the moment for what I'm planning to do with the car.

Small recap:

- Keep my Disco V8 MY2000 and put in a long range tank, that would be a 150l one and would make that I have the same range as a standard TD5. A tank cost me 1400 dollars without install... Worth it?

- Buy a Disco TD5 MY 03 or 04. Built everything that I have on my V8 over on the TD5, make the V8 standard and sell it. Worth it?

- Sell the Disco V8 as is and buy a diesel Defender? What engine should I go for on that one?



Thanks already!

[ozscott]

Mate you have to do the sums and also take into account that a lot of D2's have been abused and have been let go in many areas including the chassis.

Also if you put in a Brown and Davis 142 long range tank you will get, in a fully laden vehicle reading for touring, better range than a fully laden TD5 with stock tank...My understanding is that a lifted TD5 with roof rack and roof tent or similar size things on it, bull bar and absolutely maxed out in the storage department, 2 batteries etc, is probably only getting on the highway about 3 litres per 100k better than a V8. So that is about 22% worse economy in such conditions compared to the TD5. Unladen is a different story with non chipped TD5's on pretty stock vehicles getting much better economy than the V8.

Cheers