i;ve got to be careful here as i dont what to be playing devil's advocate but its a fact that even the best conversion or indeed factory lpg job in a new car with clearly a clean engine the lpg engine will be 10% worse on fuel mpg really doesnt matter what people think or how many think that way lpg cannot physically give the same mpg as petrol just as petrol engined cars cannot give as good mpg as diesels.now there is a new problem appearing on post 2006 car cocerning lpg damaging seat valve that at least one well know LPG conversion specialist has suspended doing conversions on post 2006 cars... note.Fiat which on the continents has been offering LPG and methonol vehicles for decades shows clealry the difference in performance and economy to differ between the differing fuel options..
link to LPG PROBLEMS
http://www.amrautos.co.uk/index.php/lpg-systems
link to LPG PROBLEMS
http://www.amrautos.co.uk/index.php/lpg-systems