City - highway?? Wouldn't MPH be better to use

[peteo48]

Somewhere in these forums is a post from a member who uses a formula based on the US EPA fuel consumption tests. In those tests city mileage averages out at 22 mpg and highway at 49(stand to be corrected here) and he used those to establish the percentage of city and highway. Coming from the UK I've been using the European system (soon to be changed - it was unrealistic anyway) where "urban" driving averages at 12 mph and extra urban at 39 so my city figures are really based on the urban cycle. It shows I do 75% city and, to be fair, that's a pretty fair reflection of what I do.