The rules are simple – the car which uses the least fuel over the set route win.
In the event of a tie the greater number of correct observations will determine the winner/s.
There are two classes only – red cars, and cars which are not red – I think that’s right?
Or maybe it’s for cars less than two litres, and cars above two litres.
Note – the rules for 2011 involved the weight of the car to make the competition more even, so the calculations were based on l/100 km/tonne.