Diesel / LPG Mix

Quite honestly mate I reackon it would be waste of money, would take years to recoup the outlay, and you can be assured if too many people go gas the price WILL go up , then there is the lost space taken up by a gas tank, and the risk of it exploding ,

Doug

Despite what Doug says, I believe it's worth a decent look.

I have some (small amount) of experience I can lend to the discussion.

Firstly, my newish (to me) truck has LPG injenction and has had this since April 2001 (it was built in October 2000 and converted from a 4.2TD to a 6.5 V8 Chev Diesel in November 2000). So, from that perspective alone, the fact that the vehicle has done about 190,000klm and the LPG hasn't "blown up"....nor has the engine..... it's gotta be a fair indication.

Secondly, power-wise...... I have no hard and fast dyno figures etc. In my case too, the 6.5 chevvy has a goodly portion of torque and reasonable power. Switching on the LPG switch gives a small, but noticeable, boost. However, I have a mate who just had his 4.2TD Patrol converted (using CURRENT technology, unlike my truck's old-fashioned version). The difference in THAT vehicle is nothing short of astounding!!! I drove it for a short distance with the gas off, and then with it on. Being another bloke's truck, there was no way I was gunna drive it like I stole it ( as the was sitting beside me). However, I then had the chance to go as passenger while HE drove it like he stole it!!! Man; it goes better than my 6.5 v8.

Thirdly, fuel economy wise..... I have another mate who also has a 4.2TD Patrol. We both tow the same brand of camper trailer and I reckon my rig would be a few hundred kilo's heavier than his. On a recent trip from here (Kadina) to Woomera, then across to Farina, Marree, Oodnadatta, Dalhousie Springs, Chambers Pillar, Alice Springs, Ayers Rock, then back home down the blacktop.......I used less fuel (combined cost of LPG and diesel) than he used straight diesel in his 4.2TD. Probably not a fair comparo because the 6.5 revs less at 100k/h due to 35" tyres. Typically I was doing 2000rpm while he was doing 2250rpm at the same speed.

So, there's a few points to think about.

My concern would be the longevity/reliability of the engine, you get nothing for nothing there is always a consequence of pulling more power out of an engine.
These modern small turbo intercooled engines are already running at very high outputs for their cubic capacity so any attempts to extract further power may overload cooling, lubrication and other systems.
Given that some have already shown they will last no longer than a petrol engine (if that long in some cases), are very fussy on fuel quality, (mostly because OEM filters may not be up to the task) and most owners turn their vehicles over on relatively low mileage/age basis most will not realise any cost savings.
The investment is usually pretty good for the second and subsequent owners though as in Roachies case.

Fact is government policy is to bring the tax up on gas slowly until it is same as on petrol. So I read anyway.

Owen

Landy, ust a thought I am fairly sure on the Diesel Gas Australia website (or someone similar) they have actually done the conversion on a 300Tdi that might help you a bit. (Keeping in mind of course it is within their interests to quote the best case!

Have a guy camped beside us right now with a 105 landcruiser who has had it done.

Says it is an improvement power wise but not as much as he wanted. Good for the fuel economy. Says if he runs it without the gas it is SLOWWW..... Towing a KK camper.

Cost him $3000 with $600 rebate. He missed out on the $2000 rebate by a month. But of course the price has gone up now by about $1000, funny that.

The other point to mention is that usually a small gas tank is installed because gas is only added ontop of the diesel, so not much is used or consumed.... To go through 70 litres of gas on such a conversion may take 400 litres of diesel....Roachy might be able to give you comparison figures on amounts....from what ive picked up listening in, the gas system works alot better on direct injection diesels than it does on indirect...and i would be doing this conversion if you intend to keep your limo...
Andrew

Baz,

There is a place near Penrith (Kingswood) that does the gas installation for diesels.

Might be worth a word with them. Can't find the phone number just know but I will keep looking.

Wayne

My 3.0 TD Jackaroo was done about 3 weeks ago, limited fuel economy results as such. But to date, power up about 20% (guess), torque up, revs effortlessly up to red line now. Fuel economy has risen from 12.5l/100kms to 10l/100 kms, roughly 23%, gas usage is up a little at the moment but hasn't been checked since installation (requires a check after consumption tests) but is suppposed to be set at 20Lgas to 80L diesel for max power:economy gains. I think defenders have an 85L tank, so you will need about 20L. Results on abovementioned website were much better than these for the Defender TD - more like 30% plus gains, may indicate they have a low diesel combustion rate unmodified in standard form, or the results may have been tweaked with other mods (like the 4.2TD on the site - quite useless results given they have added larger intercooler etc).

Im not too fussed about longevity - surely an engine can withstand pressures on it brought about by close to 100% burn rate in the combustion chamber. You could do more damage by continually flogging a non-LPG engine. I need less right foot now to go the same speed/accellaration rate, the engine doesn't work as hard, tows easier etc.

Performance is notably increased. I have worked out at current prices you will save about 15-17% on total fuel cost (a lot more at the moment with diesel at 129c/L plus), get an extra 200km range or there abouts, reduce exhaust emissions substantially, run with lower internal temperatures (good for engine), cleaner longer lasting oil. All good if you ask me.

Some people spend $2000 on a chip/exhaust at least. LPG gives great performance results and saves you money in fuel later. And if you run out of LPG, you just keep running on diesel!

Performance is easy to guage with a dyno - you start with gas turned off, then with gas on. Try sprints to 100 km/h on the flat, or max speed reached up a hill to a certain point to compare. You will feel a most definite increase in power and torque anyway.

Good luck with your decision. I know I'm glad I've made the change.

D-Jack

G'day Landy,
We did a Landy just recently, 97' 3Ltr Tdi. We gained 24% at the rear wheels & haven't had much feedback yet in the way of economy.
We were able to get 26Ltrs usable under the vehicle with an exhaust mod, giving him a range of roughly 850K's out of the LPG.
Big difference in torque as well. The difference in drivability is really noticable. We got 41% gains out of a 3Ltr Turbo Diesel GU, 33% gains on our own 2.2Ltr Diesel Mazda Van, 20% Gains out of a HJ60 Turbo Diesel, & the list goes on.
At the end of the day Diesel Gas is all about improving the efficiency of the diesel burn. If you consider the LPG as an accelerant, when added to the cylinder it enables you to burn more of the diesel than you normally would, giving you extra energy from that fuel meaning to do 100klm/h down the highway you don't need to put so much in, = lift your foot = less diesel used =$$$ in your pocket.
We had to fit a crank angle sensor plus a throttle position sensor. A pretty involved conversion.
Good results at the end of the day.

ive got the dieselgas system on my 105 l/cruisr,but now iam thinking of trading in the car ,this part is going to be interesting,because most dealers only want a unmodified car and others have never heard of gas in a diesel,so after spending 4 grand iam going to find out if i have actually devalued it,the other option is to take the kit off and try to sell it separately(any takers)