LPG - what mpg realitic

[magpies]

Hi
I'm looking at the possibility of buying a Disco 4.0 with professionaly fitted LPG
I do 34 miles to work 3/4 on motorway - I currently get 45mpg out of my Audi 2.5tdi
what sort of mpg (equivelant) would I expect from the Disco - I realise this is NOT an exact science, but a ball park figure will help in me.

[Phil.]

It's easier to think in terms of cost than mpg because all LPG systems use some petrol when warming up so it isn't an exact science. As a rule of thumb, take the average mpg you would get from the disco on petrol over [say] a normal week, double it and cost it at diesel prices. I get around 17mpg average on petrol over a week and the cost for LPG/Petrol over a week is around the equivalent of 34-35 mpg at diesel prices. This calculation has been reasonably accurate for a RR 4.2 S/C over 30k miles.

[JW911]

Mine is a 4.4V8 Rangie with 20k covered on LPG. You probably won't find yourself running for more than a mile before it has warmed up sufficiently to switch to LPG. In winter, I use about three-quarters of a tank of petrol (yes, over the whole winter) and in summer, very little. Generally it equates to about three tanks of petrol annually.

For your "equivalent mpg", take the petrol mpg, deduct around 17% then double it. My Rangie gives an equivalent of low 30s mpg. Alternatively, Phil's calculation is just as valid.

Edited by JW911 on Saturday 23 January 09:50