We show you the green cars which could help you beat the credit crunch.

Buying a car with good fuel economy means you’ll have to fill up less often. And the less CO2 your car emits, the less it will cost you in car tax.

But which cars should you consider? Here are five frugal motors to help you decide.

Toyota Aygo - £6,950

Car tax: £35
CO2 emissions: 108g/km
MPG: 61.4

Toyota’s swift little Aygo makes a great inner-city car with its nippy engine and four star EuroNCAP safety rating (all cars are tested for safety and rated out of five). If the Aygo’s styling isn’t to your taste, the Citroen C1 and Peugeot 107 are identical cars with different looks.

Seat Ibiza Ecomotive - £10,995

Car tax: £0
CO2 emissions: 99g/km
MPG: 74.3

The Seat Ibiza Ecomotive is one of the greenest new cars on sale today – the other being Volkswagen’s Polo BlueMotion. Both emit 99g/km of CO2 emissions and can run for a combined 74.3mpg.

Volkswagen Polo BlueMotion - £12,120

Car tax: £0
CO2 emissions: 99g/km
MPG: 74.3

The Volkswagen Polo BlueMotion was one of the first green cars to be made available in the UK and is still one of the most frugal. But adding extra kit – such as air-conditioning – moves it into tax band B at £35 per year.

Mini Cooper D - £14,420

Car tax: £35
CO2 emissions: 104g/km
MPG: 72.4

The eco-friendly version of the successful supermini emits just 104g/km. With a 110bhp diesel engine and a top speed of 121mph, the Mini Cooper D is both fun and economical.

Ford Focus ECOnetic - £16,345

Car tax: £35
CO2 emissions: 114g/km
MPG: 65.7

Ford’s efficient Focus ECOnetic has a different front bumper skirt, rear spoiler and slimmer tyres than the normal Focus, and a greener CO2 output of 114g/km – placing it into tax band B (£35 per year).

Find out more on our green cars homepage

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How do you save money on your motoring? Have your say on the Auto Trader Blog.

Disclaimer: Auto Trader cannot guarantee the above advice will always save you money.