View Full Version : Dual Fuel

Holden Hunter
13-11-2003, 12:12 PM
Hi everyone, a quick question about duel fuel. What are the actual disadvantages of getting a aftermarket dual fuel system installed?

Does it really wear out your engine quicker than normal ULP? I ask this because this is what most people say, but have a look at the old EF/EL taxi's running around. Some of these would have over 700,000km on the clock and still going strong and running 24/7 basically. Also my mates parents have a NC series 2 4ltr on dual fuel. It has now clocked up 270,000km and still runs extremely smooth. Also roughly how much power would u lose when running a aftermarket dual fuel system on say a standard 157kw EF? Is it really noticable? And when u switch back to ULP have u got the whole 157kw back?

Any replies to clarify this would be appreciated:)

29-11-2003, 07:42 AM

Have Just recently had the AUIII converted to Dual Fuel and can advise the following.

1) Get a quality installer and visit the workshop before committing. Remember, cheapest is not necessarily the cheapest in the long run.

2) I have had a Sprintgas system installed that seems to really work well with the cars normal computor.

3) If concerned about engine wear, as I was (always hear some horror stories) I installed a "FlashLube" kit that lubricates the valves etc automatically. You only have to top up the little resivour of Flashlube in the engine bay every 3 or 4 tank fulls. Adds about 1 to 1.5 centes per litre to your gas fuel costs but I think it is good insurance. Considering that Gas in WA is only 33 cents per litre, cost is not really a factor. Cost me an extra $50 to have it installed.

4) Power loss is hard to judge and depends how you drive. In normal drive I notice little difference.

5) You can switch back to normal fuel at any time and I don't think that you would lose any of the original petrol power. Maybe by driving flat out there may or may not be a small difference because the Gas injector / swirl ring is installed in the air inlet tube just prior to the throttlebody and may restrict some of the airflow, but this would be minimal. Me, with the way I drive, can't notice any difference.

Hope this helps.



Paul Stewart
29-11-2003, 07:57 AM
Thanks for the info Swampy.

Holden Hunter
30-11-2003, 09:03 AM
Thanks alot mate for the info. Really appreciated:) . Just one more question how much did it cost you for your quality system to be installed? Because if i get my car converted to gas as you said if you get a cheap system it's just going to cost you more money down the track.

30-11-2003, 03:33 PM
Dad has dual-fuel on his Fairmont.

Whatever you do, do not switch between LPG and Unleaded whilst you are travelling.

We had a blown headgasket from excessive switching between the two fuel's whilst the car was active. :eyeb

30-11-2003, 04:48 PM
Hello Again

Pricing of the install probably varies from state to state.

In Western Australia, the state government gives you a $500 Dollar rebate (from memory) off the Gas install Cost.

My lovely wife has tidied up my home office so now I can't find the invoice:ohno .

From Memory, the install cost $1,950, less the $500 rebate, total cost to me was $1,450. The conversion garage looked after the paperwork, I just paid the $1,450.

They also put in new plugs and a new air filter that was on top of this cost. They both were due for change anyway so no great grief. For a smooth running system, plugs, leads and air filter in good condition(plus regular gas tune)are paramount.

Regarding the comment from changing from Petrol to LPG or vise versa while driving. Obviously I don't know the circumstance of the blown head gasket case, although you should not change fuel types while the engine is under load. The engine should be decelerating at the time of change.

So if you have Cruise control engaged, disengage cruise first, while the engine starts to decelerate, then press the button, wait a second , then continue on as normal.

Likewise, do not change while idling at the lights in drive. Best to slip the trans into neutral, raise the revs slightly and while the revs come back down, hit the button.

As long as you don't change fuels while under load, you shouldn't have a problem. The system that I have automatically starts the car on petrol, and as per normal when the engine starts the revs flick up to about 1000 rpm, as it comes down, the gas automatically cuts in. The change is inaudible and you can't feel the change at all.