Peugeot has introduced a new lightweight, eight-valve, 1.4-litre HDi turbo diesel engine for its 206 and 307 ranges.

With slightly different tuning, the new engine develops 68bhp in the 206 and 70bhp in the 307. Fuel consumption on the European combined drive cycle is 65.7 mpg for the 206 and 62.8 mpg for the 307.

Carbon dioxide emissions levels, the basis of road tax in the UK from next year, are claimed to be the lowest in each model's class -- 112 g/km and 120 g/km respectively.

The 206 1.4HDi has a top speed of 104 mph, and accelerates from 0-60 mph in 15 seconds, while the 307 has a maximum speed of 102 mph and travels from 0-60 mph in 16.3 seconds (16.5 seconds for the 5 door version).

The direct injection turbocharged diesel engine weighs 98 kg, some 50 kg less than the 1.9-litre motor it replaces.