2011 Mercedes-Benz S-Class S250CDI four cylinder

Mercedes-Benz has a new strategy up its sleeve and wants to jump on board the green movement train and tackle its rivals (BMW and Audi) by offering its most expensive, most luxurious model - the S-Class - with a super-green four cylinder engine.

BMW is said to have budgeted 1.2 billion euro into fuel-saving technology development, while Mercedes-Benz has reportedly put away 1 billion euro to the same cause. Mercedes-Benz says it has always wanted to achieve excellent fuel economy whilst retaining true Mercedes-Benz performance though, especially on the S-Class. And with the S250CDI, that's certainly the case.

The S250CDI uses a 2.2-litre turbo diesel engine offering 152kW of power. Up to 500Nm of torque is also available from as low as 1600rpm. Mercedes says the S250CDI uses just 5.7 litres of fuel per 100km, putting it well and truly in green car territory, and emits just 149 grams of CO2 per kilometre.

It's too early to tell if the Mercedes-Benz S250CDI will be available in Australia, but sales will begin in Germany early in 2011. It's also expected to go on sale in Asian markets some time next year.