LPG Fuel economy with injected Gas

I promised to post this a while back. I now can.

Our new Ford Courier 4L V6 was fitted with a Prins, Sequential Vapour Injected Gas System about a month after we got it.

Describing it as simply as I can it makes the engine run on LPG as it does on ULP. As opposed to the older style LPG systems that effectively changes a fuel injected engine back to carby one when running on LPG, hence the dramatic increase in consumption running on LPG with the old system.

As near as I can work it out, the Courier uses about 10% more on LPG than ULP. I do however put some of this down to the extra weight of the LPG tank and the fact I have put the spare wheel on the roof rack which cannot be helping the aerodynamic drag.

To offset that, it still uses some ULP on start-up; the system will not switch to LPG until the motor is warm, typically about 3 km on a chilly Melbourne morning.

So, on balance, I reckon the modern LPG system uses around 10% more than ULP. This stands scrutiny, as I had an RB30, 3L Petrol (Carby) GQ Patrol years back and too had it converted to LPG and the difference was about 10%. That is, on two "like for like" LPG conversions the 10% is constant.

Anyway, at around 20L/100 Km with LPG at 60c/L and Diesel at $1.45/L, I would need to find a diesel Twin Cab Ute that could return 8L/100Km. They don't exist. Certainly not with 154kW and the way I drive. I'm no lair (these days LOL), but neither have I ever driven with economy in mind.

Jim.