how do i work out how many miles to the gallon my car does when petrol it's sold in litres, i put $50 ( have'nt got a pound sign ) of petrol in my car and it says i will do 377 miles on that, thanks for any replys
I keep my petrol receipt which has the number of litres on. Later I use a calculator to divide the number of litres by 4.54 which gives the number of gallons. I then divide that number into the miles.
Example:
34.76 litres becomes 7.65 gallons. If you have done 265 miles on that fuel then dividing the miles by the gallons tells you the car has done 34.6 mpg.
Take no notice of the range your car says you have. I did 40 miles in a Mitsubishi Colt courtesy car after the range displayed had gone to zero. And that's nothing compared to the Jag driven by Clarkson in the TopGear challenge drive from Switzerland to Blackpool.
It is better to work on how much petrol you need to fill up, and work back via the mileage done since the last fill up, with 4.54 litres being a gallon.