Want to save fuel and cut down your CO2 emissions? The DTI has just unveiled the “Act On CO2” initiative to encourage car buyers to purchase more fuel-efficient motors. Auto Express has conducted its own research to find Britain’s 100 most economical motors.
The tests were conducted on public roads and take into account traffic conditions, weather, types of road and all the other variables that influence your mpg. Ten classes of cars were tested, from city cars to SUVs and family saloons to MPVs.
Ironically, if you want to get the best fuel returns from a drop top, you need to drive with the roof up. Our tests were conducted with the lid raised and lowered, but once again diesels dominated the top 10. Winner was the Vauxhall Tigra 1.3 CDTi, which out performed the 1.4 petrol version by over 10mpg. Top four seater was the Renault Megane C-C, closely followed by the VW Eos.
| Make/Model | Tested MPG | CO2 | |
| 1. Vauxhall Tigra 1.3 CDTI | 45.2 | 124 | |
| 2. Renault Mégane C-C dCi 130 | 41.1 | 154 | |
| 3. Volkswagen Eos 2.0 Tdi 140 | 40.8 | 158 | |
| 4. Vx Astra TwinTop 1.9 CDTi 150 | 40.5 | 165 | |
| 5. Peugeot 307 CC 2.0 Hdi 136 | 40.1 | 159 | |
| 6. Ford Focus CC-3 2.0 TDCi | 39.4 | 156 | |
| 7. Vauxhall Tigra 1.4 | 34.0 | 146 | |
| 8. BMW 325i Convertible | 33.5 | 190 | |
| 9. Mazda MX-5 2.0i | 33.3 | 183 | |
| 10. Peugeot 207 CC 1.6 THP | 33.1 | 171 |