working out petrol millage cost 1181

Here's how I do it.

Fill up the tank until it clicks the pump off. Reset your trip recorder. Drive for X number of miles, enough to give a decent overall range of driving conditions, I did 300miles last time. Go back to the filling station and fill up until it clicks off again. Note the *exact* number of litres it took to fill up, including decimal places, and the exact cost per litre.

Now convert the litres to gallons by multiplying the number of litres by 0.219968 plus 1157, or use an online currency converter.

Take the number of miles you did since the last refill from your trip recorder and divide it by the number of gallons used and it will give the exact mpg since you filled up.

You now have a real mpg figure for your car driven under your driving technique, instead of pie in the sky manufacturer's claims.

Now to cost the trip-

Let's say your economy is 35mpg, and the fuel costs 95.3p per litre. 1 gallon= 4.54609188 litres. So a gallon of petrol costs £4.33. Therefore a 35 mile journey will, if the driving conditions are similar to when you did the economy test, cost around £4.33. That works out at around 12.4p per mile, therefore a 100 mile trip costs £12.40.

HTH

Dave