Greenest cars
1 Smart Roadster
2 Smart Fortwo cabriolet
3 Citroen C1 1.0i
4 Peugeot 107 1.0
5 Citroen C1 1.4 HDi 6 Fiat Panda 1.2
7 Ford Ka 1.3
8 Toyota Yaris 1.0 9 Fiat Panda 100hp
10 Peugeot 206 1.4
11 Mini Cooper D
12 Toyota Prius 1.5
Source: Cardiff University/Clifford Thames