Road Test: Audi A6 2.0 TFSI Hybrid 4dr Tip Auto

Audi says its A6 Hybrid combines the performance of a V6 petrol with the economy of a four-cylinder.

This petrol-electric A6, with its 2.0 TFSI engine and 53bhp electric motor, generates a maximum 242bhp and will reach 60mph in 7.3secs, returning a quoted 44.1mpg and 146g/km of CO2. Six for the environmental price of four.

Unlike the Fisker Karma, for example, the electric power here is more an added bonus than the main event. The A6 won't go more than a couple of gentle miles in ‘stealth mode', but it does at least mix petrol and electric seamlessly, with less of the brake-regen issues we've suffered from previous hybrids.

But there's another Audi engine that melds the performance of a V6 petrol with the economy of a four-cylinder: the V6 diesel. Even the less powerful of Audi's two six-cylinder diesels gets to 60mph a fraction quicker than the hybrid while officially using less fuel and emitting less CO2.

If your big saloon is destined to spend its life in traffic, the hybrid could work for you. But consider the cost: it's expected to weigh in around £45,000 when it arrives next year, 10 grand above the diesel. Not quite six for the price of four, then...