I've had an LPG conversion in the past on a small car (Nissan Micra) - my experience is that over a long time, it can pay for itself (I did need a cylinder head replacement at my own cost as it was running very lean) - the fuel consumption isn't as good as on petrol, so you can't simply compare fuel prices - the official figures for the Micra were 44mpg on petrol, 35 mpg on LPG and at motorway speeds, this dropped down to around 25mpg. This is in a small economical car with a 1000cc engine.

As pointed out above, on basis of price, the fuel consumption on the 3.3 is equivalent to about 26 - 27 mpg. On the other hand, my 2.5crd returns around 34mpg around town and 42mpg on long runs, so is much cheaper than the LPG equivalent, plus plenty of torque and no loss of boot space or spare tyre. Personally, I'd go for a diesel every time now instead of an LPG conversion if you haven't already bought your car.

 

Thanks for all your replies..

I haven't decided what to do yet - might just leave it as is for the time being