Competition in the eco car segment is hotting up, and the Vauxhall Ampera is a real contender. Its CO2 emissions are lower than any efficient diesel or hybrid currently on the market. That means there's no road tax to pay, and it's exempt from the London Congestion Charge, too. The Ampera can be plugged into the mains to charge up the batteries (a process which takes around four hours) and can run on electricity alone for around 50 miles, so you shouldn’t need a drop of petrol for most journeys. And even when you do need to travel a bit further, economy is so good that you will rarely have to visit a petrol station. But for all of its green credentials, the Ampera offers strong performance. It's fast, features sporty looks and an attractive high-spec interior. Which is why it won our 2013 CarBuyer Best Hybrid/Electric Car award.