Turbocharger Posted October 7, 2012 Share Posted October 7, 2012 My Ninety burns a lot of fuel, so I'm not using it as much as I should. The Tdi is around 150,000 miles old and giving 26mpg. On 5k miles per year, that's £1200 - so there's not a lot available to spend to make it more efficient - this is for engineering interest and because filling the tank irks me. Looking at smaller engines, it's clear that the Tdi is a torquey beast but more modern designs are catching up. It's possible to use a reasonably simple smaller unit and still give acceptable performance - it'll never be a racing car. I'm idly wondering if a 1.9VAG or 1.9 PSA engine would give my soft-top Defender reasonable performance and 30+ mpg, even through the autobox. I've attached a table of comparisons. Thoughts? Has it been done before? Clearly it'd need adaptors making up, mounts moving etc, but there's plenty of space in a Defender bay and it'll be lighter as well. Quote Link to comment Share on other sites More sharing options...
Daan Posted October 7, 2012 Share Posted October 7, 2012 the 1.9 is a good engine, but in standard form a bit small for the size of car you are trying to move. Im getting 30 mpg, even on simex. I would start with ditching the auto and get the tallest transferbox, and you will achieve exactly what you want. Ps. the VGT you have makes it ideal to have a good lean re-tune. Daan Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted October 7, 2012 Share Posted October 7, 2012 A good service would be a starting point... My 110 returns around 22mpg and does at least 15,000 miles a year so i dunno what your complaining about! Also, land rover now fit a 2.2 engine so that's the sort of size and performance you'd be after if you used a modern engine. Quote Link to comment Share on other sites More sharing options...
Spearos Posted October 7, 2012 Share Posted October 7, 2012 For me, the cost of fuel is by far the biggest downside of Defender ownership. I always tell myself it's not too bad as it's offset by carrying out the servicing out myself, the price of parts is relatively low and of course depreciation isn't much of an issue. I must confess though, I sometimes daydream about fitting a small(er) capacity, more efficient engine, something a bit different to reduce the amount of time I spend at the pumps. Surely the actual capacity of an engine with regard to the size/weight of the vehicle it's fitted to is irrelevant? Isn't it the power/torque figures that matter? For example the VW AFN engine's figures in the spreadsheet above aren't too far off the 300Tdi figures so why would this be considered underpowered - would the 4bhp/22ftlb really make all the difference? Or is there another factor that comes into play? Quote Link to comment Share on other sites More sharing options...
dangerous doug Posted October 7, 2012 Share Posted October 7, 2012 the 1.9 out of my vectra has more power and torque than a tdi(150BHP/236LBS/FT), it will get double the mpg too. just a simple re map will take it to 200bhp. size means nothing with engines these days Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted October 7, 2012 Share Posted October 7, 2012 That double the mpg is in a lighter 2wd car, it wouldn't be anywhere near that good in a Defender Quote Link to comment Share on other sites More sharing options...
TSD Posted October 7, 2012 Share Posted October 7, 2012 The other factor that comes into play is longevity IMHO. Modern car diesels are built to be as 'car-like' as possible, with lightweight parts, smaller bearings for higher speeds. etc. The effect of putting it into something heavy and draggy like a Defender would be similar to using it in it's original home, but towing all the time. It will probably work ok, but life might be shorter and economy may be not all you expect. I'd be looking for engines that were fitted in vans, as a vague guide to how much strength they have in reserve. The Peugeot XUD is a tough little engine though, so it might be OK. There's a guy in the US put a VAG 1.4D into a series as I recall. Quote Link to comment Share on other sites More sharing options...
TSD Posted October 7, 2012 Share Posted October 7, 2012 It occurs to me you could possibly put the XUD lump in easily, using the bell housing and input shaft from a Peugeot powered LDV van, on a 4WD LT77 ? ...Or I may have dreamed it, as a use for the low mileage Mi16 lump in my shed Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted October 7, 2012 Share Posted October 7, 2012 There's a guy in the US put a VAG 1.4D into a series as I recall. There is a company in the states that puts vw1.9pd's into jeep wranglers, i think the write up said something about 36mpg that'll be us gallons as well It occurs to me you could possibly put the XUD lump in easily, using the bell housing and input shaft from a Peugeot powered LDV van, on a 4WD LT77 ? ...Or I may have dreamed it, as a use for the low mileage Mi16 lump in my shed You could probably just use the bellhousing with a defender lt77 the difference in input shaft length is negligable 10-15mm or even just bolt a landrover 5th gear extension housing on and bolt a lt230 transfer case on Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted October 7, 2012 Share Posted October 7, 2012 The other factor that comes into play is longevity IMHO. Modern car diesels are built to be as 'car-like' as possible, with lightweight parts, smaller bearings for higher speeds. etc. The effect of putting it into something heavy and draggy like a Defender would be similar to using it in it's original home, but towing all the time. It will probably work ok, but life might be shorter and economy may be not all you expect. I'd be looking for engines that were fitted in vans, as a vague guide to how much strength they have in reserve. The Peugeot XUD is a tough little engine though, so it might be OK. There's a guy in the US put a VAG 1.4D into a series as I recall. The 1.9pd's are built incredibly well, forged steel crankshaft, fracture-split forged steel connecting rods and Mahle or Alcan pistons. I have a vw sharan with the low power 115bhp 1.9pd, the kerb wieght acording to the handbook is 1949kg it has always averaged over 40mpg The hand book also states the gross vehicle weight as 2610kg with 2000kg towing limit. so vw are happy to put 4.6 ton behind one so i'd say a defender would be fine. i think the drivetrain losses of a landrover would kill some of the mpg though. Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted October 7, 2012 Share Posted October 7, 2012 Power delivery is important, the tdi's give there ooomph quite low in the rev range. Remember the 2.6 series 3's.... Alot of complaints the engine was to revvy. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted October 7, 2012 Share Posted October 7, 2012 i think the drivetrain losses of a landrover would kill some of the mpg though. Agreed. This, coupled with the air resistance characteristics of the vehicle is what will make the most difference. By my calculation comparing to my Tdi 90, you're missing out on 5mpg through your autobox. So if you're serious about fuel economy then going manual will gain you a fair bit, I get 30-32mpg out of mine and that's a hard-top. Quote Link to comment Share on other sites More sharing options...
TSD Posted October 7, 2012 Share Posted October 7, 2012 The 1.9pd's are built incredibly well, forged steel crankshaft, fracture-split forged steel connecting rods and Mahle or Alcan pistons. The hand book also states the gross vehicle weight as 2610kg with 2000kg towing limit. so vw are happy to put 4.6 ton behind one so i'd say a defender would be fine. I don't doubt they are well designed and well built, or that it has the ability to tow... but faced with the choice of two otherwise similar second hand vehicles, I'll most likely buy the one without a towbar. Most of the small diesels I've driven (hire cars) feel like the ECU is artificially holding them back at low rpms. I assume this is to protect either the bottom end or the gearbox from the torque spikes. (or do they just like making their cars drive like ****?) I had a vw small 4wd thing for a week or so, with the DSG gearbox and that was utterly hateful. Good job I didn't pay for the 'zero excess' option or I would have cheerfully crashed it and walked home. Quote Link to comment Share on other sites More sharing options...
Daan Posted October 7, 2012 Share Posted October 7, 2012 Agreed. This, coupled with the air resistance characteristics of the vehicle is what will make the most difference. By my calculation comparing to my Tdi 90, you're missing out on 5mpg through your autobox. So if you're serious about fuel economy then going manual will gain you a fair bit, I get 30-32mpg out of mine and that's a hard-top. What I was thinking, and combine it with a 1.0 transfer box and make sure you never see smoke out of the exhaust, would make things much better. Also, I now have Cruise control on my roadcar, and that makes all the difference in consumption. You think you are driving pretty constant, but you do vary the throttle a lot unintentional. Daan Quote Link to comment Share on other sites More sharing options...
Michele Posted October 7, 2012 Share Posted October 7, 2012 For me, the cost of fuel is by far the biggest downside of Defender vehicle ownership. I never complained about my Tdi fuel consumption, but the price of fuel nowadays is a serious limit to freedom...no matter what car you drive, IMHO. Quote Link to comment Share on other sites More sharing options...
Soren Frimodt Posted October 7, 2012 Share Posted October 7, 2012 Just slab in a big thirsty V8, and be done with it! No matter how good mpg I have had from an engine/ vehicle, I've always dreamed of more. As a matter of a fact, the lower fuel consumption the more I thought about making it even lower! You see if good mpg is all your vehicle has to brag about then you want it even better, The same way if you have an american V8, it's good at horsepower/ torque and great sound, so that is what you want more off, and end up putting in bigblocks etc. That's just how life is for us poor spannering-freaks Quote Link to comment Share on other sites More sharing options...
Michele Posted October 7, 2012 Share Posted October 7, 2012 I'd love to do it with my ex-military 109" IIA. I'd love a Chevy. If I had a job again, and lived in a free coutry...I would. To stay on topic, and agreeing with some of the above, I think smaller cc engines would stay with smaller (lighter) cars. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted October 7, 2012 Share Posted October 7, 2012 Certainly following with interest here! The VAG and other engines such as the volvo ones get some great power figures with a little tweaking. Would be interesting to see the MPG in a defender. Take the volvo D3 (1984cc) and D4 (2400cc) 5-pot engines used in the XC60. 163ps and 215ps respectively. Both of them return about 50mpg combined in a vehicle which is a similar weight to a 90. with a 90 being not as aero dynamic I wonder what the engine would return.... would 40 to expecting too much? I wish I had the money to experiment but then I wouldn't be worrying about the fuel cost Quote Link to comment Share on other sites More sharing options...
NickMc Posted October 7, 2012 Share Posted October 7, 2012 I always thought the Audi 2.5tdi would be a great engine to fit, the electronics would put me off though. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted October 7, 2012 Share Posted October 7, 2012 I always thought the Audi 2.5tdi would be a great engine to fit, the electronics would put me off though. This is where DieselSquirt would come in useful once it's been developed Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted October 7, 2012 Share Posted October 7, 2012 This is where DieselSquirt would come in useful once it's been developed Or convert if possible to mechanical pumps. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted October 7, 2012 Share Posted October 7, 2012 I think converting to mechanical pumps would make them work outside they original vehicle, you are going to loose some of the advantage the electronics bring! Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted October 7, 2012 Share Posted October 7, 2012 I think converting to mechanical pumps would make them work outside they original vehicle, you are going to loose some of the advantage the electronics bring! But you gain what a mechanical pump brings with it... Simplicity! Quote Link to comment Share on other sites More sharing options...
GBMUD Posted October 8, 2012 Share Posted October 8, 2012 Looking at John's VGT install, I do not think that simplicity is that much of a concern to him! My 300Tdi auto 90, admittedly a hard top not a soft top, will return 30+MPG but mostly at lower speeds. If I drive at 60mph the fuel economy is lower than driving in traffic on A-roads at 50ish. Perhaps it is driving style that is holding fuel economy back? My 1.9PD 104HP VW Transporter is capable of 40+mpg, but get a little more load on it by towing a 1000kg trailer and the fuel economy really plummets. The extra drag on a Landrover transmission may have a similar detrimental impact. John, why not consider cheaper fuels? An SVO conversion or even a full bio-diesel conversion plant at home - they are not very big and can mostly be left to get on with processes unattended or with minimal intervention. I am very impressed with Nick's (Rogue Vogue's). Chris Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted October 8, 2012 Share Posted October 8, 2012 Or just run on veg oil straight into your fuel tank like i do. 97ish pence a litre and no mucking about. Quote Link to comment Share on other sites More sharing options...
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