Skyline Owners Forum banner

1 - 4 of 4 Posts

7 Posts
Discussion Starter #1
Has anybody thought of this?

Know of someone whos done it?

Initially, I thought cheap price, cheap fuel, but I was told that LPG is 100 Octane! which makes it ideal for performance cars. (unless there is some other 'gotcha' in it's make up).

I considering having it done to my GTS, as, on paper, it would run on correct octane (Optimax is closest at 98 Octane), and would effectively double the mpg to around 40 as LPG is 39.9 pence per litre.

Anyone else have any thoughts on the matter?


102 Posts
The immediate thoughts are :

There is a 10-20% loss of economy using LPG.

It relies on the ECU correcting for the change of fuel and others will know better whether than can happen. The information about loss of power says that this would be noticed by thedriver but not by passengers. Is this a way of saying its gutless but passengers dont give a S***t.

Where are you going to put the relatively large gas cylinder. Theres precious little room in the boot anyway.

Opinionated *unt
1,593 Posts
It's possible to convert anything to LPG, I looked into it for my rotor. It's nice fuel to use but the timing and stuff is, unsurprisingly, very different so it needs some work.
Would take quite some time to pay off, even for a high mileage driver and it's likely things like fuel cells and hybrid will be more mainstream by then.

55 Posts
I have run a couple of 7 series BMW's on it for a few years now, the first one was using a vacuum assited mixer and the latest one uses the sequential injection.

There are a few +'s and -'s to the 2 different systems.

Mixer Type +
Able to flow gas at any rpm.
Can be set up for economy only 10-15% from petrol if set up correctly.

Mixer Type -
Mixer itself by design has to be a little restrictive so can cause top end power problems if not very careful with the diameter (too small lose loads of power, too big won't idle and drive very well at the bottom end).
Backfires as there is so much gas in the intake system.

Injection +
Very little power loss (740 on Petrol 310bhp, Gas 300bhp).
No damaging backfires.
Very smooth to drive as mappable.

Injection -
Very expensive.
RPM limited due to injectors (currently approx 6k rpm max)
Approx 20% fuel economy loss

However both setups still offer a large saving over petrol costs and I have heard that LPG is approx 110 octane rated.

There are prob more +'s and -'s but thats a quick few off the top of my head.
1 - 4 of 4 Posts