V8 or TD5

Hi,

I'm new to this forum but not new to Landy's but I had a 2 year gap and went back to my other fave cars SAABs (Well is was Black and had the vbig turbo charger on it!). So I'm the market for a Disco 2 as I need the extra space it has over the series1 but I need some help - TD5 or V8 with LPG fitted. In my mind from what I have read they are both as reliable as each over the only issue I have is the range one would have over the other. The V8 sounds great but if I'm filling it ever 200miles I'll start getting bored with it very quickly. The TD5 will got the distance but it would be like driving a slug again.

So what's it to be?

Bob.

TD5 is a very perky engine,

Got lots of get up and go,

V8's though will always sound better,

Hi,

A few of my mates have the TD5 disco's, and to me, are fairly brisk cars if you get a wiggle on. If you have a post-2001 (I think) with reasonably low mileage, you'll have the option for a re-map. So you can get the best of both worlds - a quick car with good mpg.

TD5 gets my vote, even though the V8's fun, but ultimately depends on your annual mileage and usage.

TD5 is a great engine to have in a D2 and work brilliantly with the auto

My first ever Diesel car in 30 or so years is a 5 cylinder off roader with a nice interior.

So yes a TS5 is fine

Bobbingto74 said:

Hi,

I'm new to this forum but not new to Landy's but I had a 2 year gap and went back to my other fave cars SAABs (Well is was Black and had the vbig turbo charger on it!). So I'm the market for a Disco 2 as I need the extra space it has over the series1 but I need some help - TD5 or V8 with LPG fitted. In my mind from what I have read they are both as reliable as each over the only issue I have is the range one would have over the other. The V8 sounds great but if I'm filling it ever 200miles I'll start getting bored with it very quickly. The TD5 will got the distance but it would be like driving a slug again.

So what's it to be?

Bob.

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Hi Bob, you sound like you enjoy driving (reference to Saab's, a favourite of mine also) so would you be thinking of autobox or manual? This is an important aspect in the choice of TD5 or v8. Allow me to explain:

It's all about the torque converter (TC) fitted to the autobox. In the TD5 setup the TC stall speed is 2600-2800 rpm. Why is this important? Because when you drive a TD5 auto it's like driving a manual car with a slipping clutch - all revs and no go, below approx 55 mph (speedo speed) and this is right in the speed range most often used, for urban dwellers. With the V8 engine the TC stall speed is 2200-2400rpm, so you get much more drive immediately and lower down the rev range.

However, if you prefer manual gearboxes then the choice is much more straightforward; go straight for a TD5 and get it remapped. This can be done on any age of TD5 and puts the power up to about 160bhp but with a big wallop of torque from about 1500rpm.

So, to some fact and figures:

Std V8 : 185bhp & 340nm of torque at 2600rpm

Std TD5 : 138bhp & 300nm of torque at 1950rpm

Remapped TD5 :160bhp & 360nm of torque at 1900rpm (these are average figures, the exact numbers will depend on the individual tuner who does the work)


So, it can be seen that a re-mapped TD5 is more than a match for a 4.0 v8 petrol, but what about fuel consumption?

I have a std TD5 manual and I get on average 31mpg and on a run 36mpg. I have had in the past a remapped TD5 auto and that gave approx 27mpg.

A v8 4.0 petrol on petrol will deliver approx 18mpg and the same vehicle roughly 10% less whilst running on gas so 16mpg.


There is a member on here - listerdiesel - with lots of experience of running LPG powered v8's and their consumption so hopefully he will chip in soon.

Hope that helps,

Cheers
Dave

Okay then, next questions. I f it's TD5 whats the best tuning method and what mileage shouldn't I try tuning at?

Bobbingto74 said:

Okay then, next questions. I f it's TD5 whats the best tuning method and what mileage shouldn't I try tuning at?

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I wouldn't be concerned about mileage too much I would be looking at condition, service history and the previous owner(s).

The main modifications to optimise a TD5 are:

1. De-EGR - remove the EGR valve;

2. De-cat - remove the catted downpipe;

3. Have the ECU re-mapped.


Dave

If you're going to chip the TD5, then comparing it with a V8 is not really valid. 135bhp against 185bhp is no comparison, especially if you tow heavy stuff like we do.

Compare a standard TD5 with a standard V8, then given the same gearbox in both, the V8 is always going to be a better drive, the TD5 more economical.

Running on LPG is the only practical way to run the V8, we have relatively small tanks but get 155 miles solo per fill, much bigger tanks are available but we wanted to keep the boot free and a full-size petrol tank,

Fuel prices are the main consideration, if you're only paying 72p a litre for LPG, consumption and range are not a big issue.

I think the TD5 is hard work to look after, the V8 tends to be plug and play for most good ones.

We have two V8's on LPG in the family, probably the best tow car for long distance you will find.

A bog-standard TD5 is a nice car, but most get modified in some way to improve performance.

Peter

I guess it's going to be TD5 then as we'll be some long distance trips/overlanding nothing extreme just UK and Europe mainly. I know LPG is more common in Europe but trips up to Scotland could be err a little too adventurous.

Thanks for the info guys very useful.

Bob

The TD5 IMO is better suited with a manual box. Can be Hard work around town between 1st and 2nd gear but once in third & upwards much better than the auto.

Beware though, 95% of the time a TD5's remapped it WILL warp the exhaust manifold!

HTH

robhew86 said:

The TD5 IMO is better suited with a manual box. Can be Hard work around town between 1st and 2nd gear but once in third & upwards much better than the auto.

Beware though, 95% of the time a TD5's remapped it WILL warp the exhaust manifold!

HTH

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95% ? And where did you get stat from.

Pretty much every TD5 I know that's had a remap, ends up with snapped studs/warped manifolds.

robhew86 said:

Pretty much every TD5 I know that's had a remap, ends up with snapped studs/warped manifolds.

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I must be one of the 5% lucky bastids then. I still think 95% is way off the mark.

blackstrat said:

TD5 is a great engine to have in a D2 and work brilliantly with the auto

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Agree. I have one too.

As Lister said, the V8 is great, but if you want a big range between fill ups on LPG you may well end up compromising your boot space.

I would add a couple of other things to Biglads list before you do the re-map, which would be a bigger intercooler and consideration of removing the centre box - some don't get along with this mod as it can make it a bit more "boomy" in the car when it's pulling. I would do all other mods before the re-map, so that it will bring out the best in them. Costs would be about the same as a properly done LPG conversion and you could spread that cost as budget allows.

Mine is a manual, so I can't comment on the autos.

As for the exhaust manifolds, it is common for them to warp and snap studs (there are enough threads on here to prove that one if you want to dig around) so many owners fit stronger Wurth studs and de-web the manifold with an angle grinder to stop it warping.

I must have had 6 TD5's through my hands in the last 10 yrs and NONE of them suffered from snapped exhaust studs and warped manifolds.

I do wish peeps would just comment from their own experience, rather than here-say.


PS Can't see the value in a larger intercooler myself, perhaps £500 for a good one takes some swallowing.

With respect Biglad and as I mentioned, there are plenty of instances on this very site of warped manifolds and snapped studs, both in the D2 and TD5 sections. So more than heresay I would say.

Maybe this issue could also be down to driving style, with those who tend to "make better progress" more often being the ones who suffer the warping and snapping issues.

Intercoolers are a big layout I agree, but I got a genuine Serck from Paddock for £360 including vat and postage. Everyone else (including going direct to Serck) seem to be around £200 more.

I hope to fit the intercooler next week if I get the time so will keep you posted on whether or not I think it was worth the money.

Maaarrghk said:

With respect Biglad and as I mentioned, there are plenty of instances on this very site of warped manifolds and snapped studs, both in the D2 and TD5 sections. So more than heresay I would say.

Maybe this issue could also be down to driving style, with those who tend to "make better progress" more often being the ones who suffer the warping and snapping issues.

Intercoolers are a big layout I agree, but I got a genuine Serck from Paddock for £360 including vat and postage. Everyone else (including going direct to Serck) seem to be around £200 more.

I hope to fit the intercooler next week if I get the time so will keep you posted on whether or not I think it was worth the money.

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To be honest my observation was more aimed at the "95%" comment, although I still believe the number of cars, across the market, not just on the forum, that have suffered with warped exhaust manifolds is small, I have no way of providing facts; but if the general principal of auto forums also applies to this issue, the owners who don't complain on forums about failures far outweigh those that do and that would be more of a straightfoward comparison between TD5's sold and TD5's on here with reported problems.

All I'm trying to do is bring a little perspective.

Dave

PS That SERK intercooler sounds attractive, do you have any experience of an installed version? How much more cooling? How much more URGE? The Paddocks ad doesn't give any facts at all.

thebiglad said:

To be honest my observation was more aimed at the "95%" comment.

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The 95% figure was not a "proven" percentage figure, but just so people kind of got the jist.
IMO and experience, if a D2 TD5 is remapped there is an extremely likely chance you will snap studs/warp the manifold and in the long run a £300 remap (and yes, the results of remapped D2 TD5 I have seen have been very impressive) could end up costing you more and it's a hassle having to change the manifold over.

Don't let me put anyone off remapping their TD5 but just BEWARE of the potential issue you may/may not suffer.