[CyberMrT]

Just had a Prins system installed on my L322 4.4 V8 and was wondering if the on board computer should still read the correct MPG when using gas?

It seems to be going up and down inline with the type of driving I'm doing?

Haven't yet filled up so can't compare with actual use of gas?

I used to get average of 18.5 on petrol and currently the comp is showing 17.5? I would be quite chuffed if this is correct?

 

[Locky]

No the onboard stuff will not give you any correct figures while running on lpg. The LPG flow rate is simply tuned to run so that your cars ecu sees a similar injector rate timing as it would if running on petrol. The amount of gas being injected is not relative to the amount of petrol that WOULD be injected so you will get an incorrect mpg figure from the onboard.

 

[Locky]

I tend to get about 16mpg on gas by the way.

 

[fisha]

I'd say it over estimates the mpg slightly on the display.

 

[CyberMrT]

Thought as much as I'm now getting 20-22 MPG on LPG on the on-board computer, I assume this is all relative if I calculate the percentage i actually get in real terms compared to the obc, then just reduce the figure shown by that percentage each time...