Originally Posted by JonnyBravo
How many miles a year do you expect to do ?
The kits do pay for themselves quicker than you think.
You will lose a few mpg on gas but obviously the fuel is less than half the price of petrol, there is apparently a small loss in power but I've not noticed anything myself.
Drop me a PM if your serious on a conversion

average do 25,000 mile a year; just commuting to work
25,000 mile @ 25mpg @ £1 per litre = give up