Time to go ecomental

You wouldn't believe how difficult it is to find a simple list showing the cleanest, greenest, most fuel-efficient cars in Britain…and how much they cost.

Major magazines and websites dedicated to cars fail to publish a simple table listing the three most important factors: price, mpg and C02 emissions for individual models.

So I'll just have to compile it myself. Here goes - this is THE list of my ten best for cleanliness, fuel efficiency and frugality.

1) Ford Fiesta ECOnetic 1.6 Diesel which can be ordered for £11,845. This supermini can do a world-beating 76.3 miles per gallon overall. Its C02 emissions figure of 98 grammes per kilometre can't be beaten by any other car either. It is the cleanest, least thirsty model on the planet.

2) Volkswagen Polo BlueMotion 1.4D at £12,125 almost performs as well as the Fiesta with figures of 74.3mpg and 99g/km. And traditionally, Polos hold their values better than Fiestas, which makes them great investments as new cars.

3) Seat Ibiza (old shape) Ecomotive 1.4D is £11,000 and has identical figures to the Polo because it has the same engine. But a far more desirable version of the Ibiza has just gone on sale. And for the time being, there isn't an Ecomotive derivative. Be patient, wait for the arrival of the Eco model before placing an order.

4) Mini Cooper D 1.6D is expensive at £14,190, does 72.4mph and has a C02 figure of 104 g/km. But this is the greenest, least thirsty British-made car and it holds its value even better than the Polo. Mini Clubman with same engine is a £15,400 68.9mpg, 109g/km option.

5) Citroen C1 1.4HDI costs £9,125, does 69mpg, pumps out only 109 g/km and is therefore the cheapest of the bunch. Group 1 insurance rating makes it ideal for young drivers. The 1.0 Petrol is good too, boasting 61.4mpg and 108g/km.

6) Skoda Fabia Greenline 1.4D, £11,495 has slightly lower fuel efficiency (68.9mpg) and higher emissions (109g/km) than its sister cars, Polo BlueMotion and Seat Ecomotive. But for £12,495 there's an estate version and it qualifies as the world’s greenest and most efficient load lugger.

7) Fiat 500 1.3D, £9,300, 67.3mpg, 111g/km. Shame about the group 4 insurance, but this is the best city car of the bunch. Also consider the £7,900, 1.2 litre petrol version that does 55.4mph and emits 119g/km.

8) Toyota Prius 1.5 petrol/electric costs a minimum of £17,777, a maximum of over £20,000 and is too expensive. What you’ll save in fuel bills you may lose by paying a high sticker price. Official fuel consumption figures of 65.7mpg are hard to achieve in the real world. C02 levels are excellent though at 104 g/km.

9) Ford Focus ECOnetic 1.6D, £16,045, 65.6mpg, 114 g/km. Unlike the Prius, this car is highly fuel efficient in everyday conditions, I squeezed 65.7 out of it - without even trying. Therefore it is THE most economical car I've ever driven.

10) Audi A3 or A3 Sportback 1.9D range starts at £16,665.The A3 holds its value well and 62.8 mpg plus 119 g/km are more than acceptable for such a prestigious car. Offering identical fuel consumption and emission figures are diesel versions of the Fiat Bravo, Kia Cee'd, Hyundai i30, Volkswagen Golf and BMW 1 series, but the Renault Megane 1.5 D manages 62.8 and only 117 g/km.