Me again! I posted on here a few days ago and got some excellent help and advice (thanks again!) and thought i was sold on a diesel, but i've started looking at the petrol engines with LPG conversions. I was just wondering what people thought of them? i'm guessing the mpg is the same as a petrol engine anyway, but how does it work out cost wise? i.e. how much would it cost (ish) to do 100 miles in a diesel and how much would it cost in an lpg 4.0/4.6 petrol?

i have a 4.6 fitted with a prins multi point system. I have been very pleased with it. I preferred it over the diesel as when i test drove one i found it to be dangerously slow. around town i do 160 miles to a tank about 66 litres (90 litre tank but you can never fill to top) at the moment i am paying 45.4p/l The most i have done on a run to a tank was 220 miles I did work all the figures out once as the car is not as efficient on gas around about 85% i think mine is doing the equivalent to about 19mpg around town and 36 mpg on a run which i think is on par if not better than a diesel. With the performance bonus. But you must be careful there are some shocking systems out there i would only go for a multi point system and keep away from single point.My multi point runs the same as if on petrol no missing you can't even tell when it switches to gas

I have a 4.6hse lpg i travel to london from hull ,i get 232 miles to a 90lt tank cost £42(sory about caps lock stuck on).

Hi i have a4.6 hse and i get between 230 + 265 out of 80 usable litres of gas { local runs} .

So they are actually pretty economical then... very tempting! Whats the difference between single and multi point systems? And which engine is more/less likely to give me trouble - diesel or petrol?

the petrol engine is shockingly notorious for slipping liners and cracked block, but if you get a good one and look after it then they are a joy to drive. the diesel can be sluggish but has fewer problems than the petrol version!