Calculating motor long distance travelling costs

wordsfan

Can anyone tell me the most accurate way of calculating how much petrol my car will use on a long distance journey based on how much petrol i use on my normal short distance town driving? I know generally per mile its less as not so much waiting at junctions and generally you use less when travelling at higher speeds, but can someone tell me a relatively simple way to calculate this?

Hammyman

No, there is no simple way of determining it. You could get the manufacturers combined MPG and work to a pessimistic value based on that but other than that, its a guess. It also depends highly on how you drive as well.