Volvo 740 Trivia.

[Laird Scooby]

Originally Posted by john.wigley

I haven't investigated the economics of LPG in detail, 'Laird Scooby'. I know that it is a lot cheaper than petrol in terms of pence per mile, but then there is the cost of conversion.

Take my V70, for example. It does around 3 - 4 thousand miles a year at an average of 29.5 MPG. It is worth maybe 500 pounds at best. I imagine that the cost of conversion would not be economical in my case, both in terms of value added to the car and the likely payback period given my low annual mileage. As I said in another thread, I am happy to pay the small fuel cost penalty associated with a larger engine.

Regards. John.

The majority of the cost of the conversion is labour John - if you could fit it yourself, you'll save a huge amount. You could also save even more by using secondhand kit then renew the parts that break as and when. My last one cost me about £300 all in using mainly secondhand parts but with some new bits as i found certain parts just can't be trusted secondhand.
However the larger/more expensive parts of the kit are generally fairly reliable, even secondhand so it tends to be the smaller/cheaper bits that can fail or aren't reliable when used secondhand.

On that basis, if i use your figures and say 3k miles a year at 30mpg, that would be about £600/year on petrol or about £300/year on LPG representing a payback time of 1 year - after that it's all reduced running costs and an important thing to consider if the car is a "keeper".

Buying new and having it fitted, you're probably looking at about 5 times the cost so obviously, 5 years payback time. Again, after that, you're saving about £300/year at current prices.