Originally Posted by Christian and Beccy

"Well, I filled my tank on 15th of June, in the year of 2006. The temperature was 21.5°c with an ambient barometric pressure of 1011mbar. Using my calibrated fuel measuring equipment, which fits inline with the fuel displacement facility at my local BP, I imparted 45.63 litres of fuel. Upon my return to the same filling station on the 24th of June, some 9 days later, I put 43.19 litres of fuel into the tank. However, on that day the temperature was 19°c, although the barometric pressure was the same. I can hereby conclude that my vehicle covered 163.25 miles on 43.19 litres of fuel, making a combined average of 3.78 miles per litre of fuel."

Hope that's OK.