Thread: Tdi into a petrol discovery?

With diesel at about $1.30 ltre compared to LPG at 80 cents and Diesel only being 20 to 25% more efficient than Petrol would the cost of the conversion be worthwhile

If the car wasn’t already on lpg the cost to convert if living in hobart is not viable. If living in melb/adel/syd then it would be a goer. I’m heading to Melbourne on Monday, might just take the v8 over and sell it there where the low lpg price makes it very viable to run the vehicle.The injected lpg gives almost the same economy as petrol and with the right tweaks to ignition it gives more than enough torque. I bought a little 1.8t excavator to do some work around my house and with the weight of the trailer and buckets was getting borderline (actually, past it) for the tdi. I was looking at buying a 2.5t excavator (which got sold on me at the last minute) and ended up buying the v8 to tow it. the torque on it is amazing. 1.8 tonne excavator + buckets + 580kg trailer plus heaps of wood working/building equipment/tools (+ my dog) and there’s no doubt the load is over 3 tonne – pulls it effortlessly. I had no concern the motor can pull it all day long. All the drivetrain is in great condition, all very recently rebuilt. Pulling 3 tonne + with the tdi and its drivetrain will put too much strain on it. I get the feeling the closing chapter of the large petrol motor is approaching (some say it’s already here). Now, if they could get the diesels to sound like the v8’s…..

Philip - a second car would be nice but have a place down the huon where I need 4wd, there is a lot of wildlife on roads here at night but of more concern are the log trucks and other large vehicles. You wouldn’t stand a chance in a small car. Now, if the 2003/4 td5 would hurry up and come done in price. They are too overpriced still. Though I don’t know how they would stand up (motor + drivetrain) to the strain of pulling heavy loads. JC down here says he fits Tombie’s chips and they go very well. Spoken to quite a few people who say the newer diesels need more time to prove they can consistently achieve the higher km’s the older ones get. They are of the old school and maybe they need to understand these higher stressed diesels are engineered to cope?

Carlos – sorry, heading interstate. Have enjoyed the days out with yourself and the other landie people over the last couple of weekends. Will keep an eye out for what’s on when I get back.

Originally Posted by isuzurover

Not necessarily.

Pendy in the US has done lots of tdi conversions with the V8 ZF


300 tdi in a 97 automatic - The D-90 Source

Not exactly a direct bolt in though is it, economically speaking it would be better just to get the matching ZF or R380.

There some one selling a 2.8 IZUZU conversion for a V8 Land Rover on fleabay , he had it in a Rangie, wants $3k complete, engine and hoses etc. He reckons it only did so many ks, but in actual fact you can't tell how many ks it had on it before he put in in the rangie.

i apologise in advance for hijacking my own thread.

Ok, well currently on way back from walking up in flinders and gammons ranges. Geez this car is a bugger, these V8’s are just so much fun to drive around and the sound……so it’s got me thinking what’s left that I haven’t thought of for sorting this bloody motor out to get better economy before I jump into putting a diesel in. already put in the oxy sensors, put EDIS in and out and had dizzy regraphed for lpg, got software for tuning lpg mapping, had lpg injector banks machined as oxy sensors were showing different flow rates per bank and when I pulled them apart there were manufacturing tolerances way out of spec. people will say yeah, it’s a 4.6 so what do you expect? Well what I did expect when I bought the car was what the bloke I bought it off said he was getting which was 20-25 litres around town and never less than 250 km from the 62 useable litres of lpg. Well after all the work I have done I have only just achieved 25 litres per 100 km around town but this is driving with the intent to maximise efficiency not normal driving practice. I paid top dollar for the car as it had 20k on 4.6 motor and diff’s and transmission were all recently rebuilt so should provide a reliable vehicle for towing and be equivalent to the running costs of a diesel. So in short the bloke I bought it off is not on my xmas card list but I digress…….

Whilst sleeping on the river beds it gave me time to think a bit more about the engine options. One thing worth investigating was what impact the plenum is having as though it is a 4.6 motor it still has the 3.9 plenum. A photo of the 4.6 plenum shows it to be taller. When the EDIS was connected it verified what the aftermarket vacuum gauge was showing, when cruising the gauge would be in the zone for fair and poor economy (near 0 vacuum end) and not in the ‘drive’ zone (1/2 way along the vacuum spread). In my uneducated mind I was thinking that this would explain the fairly poor top end as the motor simply can not get enough air in. the motor has enough torque that this lack of top end power doesn’t stop the car being driveable. But will this impact the fuel economy around town or cruising on the highway? I’m not worried about the different size of the AFM pipe as I’ve read enough from some of the identified experts overseas that this plays a minor role when benchmarked on a dyno between the two sizes. For those interested it was shown to be around 2-3 hp so don’t always believe the sales spiels.

If the 4.6 plenum will make a difference, any one know what changes have to be made to get it to fit eg stepper motor, tps, throttle cable assembly, size of air intake etc?

If the plenum won’t improve efficiency the other option worth looking at was to put a 3.9 back in. keep the heads (they are setup for lpg injection) and then swap out the block. If this was the way to go I would look at putting in a new 3.9 block so if the car is set up for lpg is there any thing special to try and get done on the block? philipA has the thor manifold but I think that mainly provided more torque rather being a fuel efficiency measure.

As I’m traveling through Adelaide I’m hoping to drop in to bee utey to see if he can weave some magic on it. There is no substitute for those who have experience of installing lpg in land rovers and reading his responses on this forum he seems to be the man.

Any helpful advice much appreciated.

Thought I’d pre-empt some of the replies :
Get a diesel – already got a tdi, can’t do what the V8 does with towing and nothing like the driving experience. Fuel cost should be approx the same with hobart’s rip off lpg prices.
Get a td5 – only ones to get are 2003/04 model and these are still overpriced and a decent one with say 130k on the clock still $21-24k and if towing how long to a driveline component goes? Plus you do your dough on depreciation and that leaves a lot for fuel for the V8 (but shouldn’t be a difference in fuel costs with my planned use) and they go rat a tat rattle as against the harmonious burble! Oh bliss.

When are you back Brett? Hope you are slowly sorting out the motor, and yes I agree that you should keep the beast. Maybe you need to drive the tdi around town and leave the V8 for weekend jaunts.

Talk when your back.

Hi carlos – should be heading back in about 3 weeks. Got to head over to Philip island and put a couple of decks and a verandah on my sister’s holiday house. Don’t mind missing a bit of july, it’s the coldest month in tassie! Will keep an eye out for outings. Did the lambda sensors fix eliot’s fuel problem?

Good to hear your doing well. Look forward to more outings.

yes, Eliot changed the oxygen sensor thingamabobs and now runs much better (for a Paj )