We have 2 LPG vans in our fleet, a Vauxhall corsavan and a transit connect.
Both are factory built, and are fantastic.
I have my doubts about the online calculators though, to give you an idea the corsavan gets 30mpg on gas, the connect is running at 22mpg which are both a lot lower than I expected.
What makes the difference to us though is that we have a local calor centre where the fuel is 29.9ppl as opposed to the 41ppl that you end up paying everywhere else.
I have therefore had bigger tanks fitted, 100 litre in the corsa and 200 litre in the connect. This means we never have to fill up elsewhere as they have a range that can get anywhere in the uk and back. With the 40 litre tanks that come as standard you can't get very far at all which in turn means you are paying that dreaded 41p or filling it up all the time.
Bear in mind that our vans do 100,000+ miles a year and therefore the savings are enormous to us (about £5,000 per vehicle)
You really need to be doing a lot of miles to make them pay due to the costs of conversion, so do your sums carefully.
HTH
