Citroen has announced its most powerful production engine, due out later this summer.
The new 240bhp 3.0-litre V6 diesel engine will offer more power as well as better fuel economy and lower carbon dioxide (CO2) emissions than the current 2.7-litre V6 diesel unit.
Tweaks to improve fuel economy include a system that recovers energy during deceleration or braking.
Coupled with a six-speed automatic gearbox, the engine promises an average of 38mpg, an improvement on the 2.7-litre engine of 13% in the C5 and 17% in the C6.
The engine's CO2 emissions of 195g/km will put both cars into band J for road tax. For registrations in 2010/2011, this will save drivers up to 325 compared with the 2.7-litre engine.
The engine will be compliant with Euro V standards, which will become compulsory for vehicles from January 2011. It will be introduced to the C5 and C6 ranges later this summer.