Britain's cleanest cars - Family cars

What Car? Greenest Family Car: Toyota Prius

Beloved of celebrities and even cabinet ministers, the Prius continues to revel in its status as Britain's cleanest car.

The five-door Prius uses battery power to back up a 1.5-litre petrol engine and emits just 104g/km of CO2, the lowest of any car on sale.

The battery is recharged during braking and coasting, and it can propel the Prius in utter silence at urban speeds.

You'll have to drive gently to get near the official 65.7mpg in a bid to claw back some of that list price premium. However, annual road tax is just £65, and there are savings for company car drivers and Londoners won't have to pay the Congestion Charge.

Other than price, there's no compromise – it's roomy, well equipped and offers a decent drive.
Price: From £17,780
MPG: 65.7
CO2 emissions: 104g/km
Exempt from London Congestion Charge

Vauxhall Vectra 1.9 CDTI 8v (120) Estate
This is a great big hulking estate with a 540-litre boot, yet still rated to return 48mpg on the combined cycle.

Unlike the hatch, the estate gets Vauxhall's particulate filter, which traps diesel soot and cuts harmful emissions massively.
From £19,185
MPG: 47.9
CO2 emissions: 159g/km

Peugeot 407 1.6 HDI FAP
It's a full-sized family saloon (or estate), yet the figures read like it's a supermini.

The official CO2 rating of 145g/km is impressive, as is an average of 51mpg (61mpg on the open road), but every 407 HDI also comes with a particulate filter, which reduces harmful diesel emissions to negligible amounts.

Finally, the 110bhp 1.6-litre diesel engine has sufficient power to ensure that you need never regret your decision to go green.
Price: From £16,545
MPG: 51.3
CO2 emissions: 145g/km