I've got an old style (Nissan built) 2.4L Maverick that I bought with an LPG conversion and it saves me a fortune.
Only things I'd say are.
1 Check out how easy it is to get LPG where you are and where you go regularly. Ie in Lincoln IIRC there is only one outlet, Shell station on the northern "ring road" and another up at Caernby corner, think its a long way down the A46 before you find it and not sure where theres any heading east.
2 Have a look at the mileage you do and calculate the pay back time, there is a distinct possibility the Mr Darling will increase the duty on LPG tothe same as petrol in a couple of years time, there is only a commitment to keep it low for the next couple of years, can't remember when exactly but I remember I found out really easy using google a while ago.
