Yahoo! Cars UK has come up with a list of Five of the most efficient cars. This was based on fuel uses and emissions. They are listed under 5 different classes :
City slickers
Fiat 500
Compact superminis
SEAT Ibiza Ecomotive & VW Polo Bluemotion
Family hatchbacks
Ford Focus Econetic
D-segment saloon cars
BMW 318d
Compact SUVs and crossovers
Ford Kuga
Read "Five of the most efficient cars in their class"