Mercedes is secretly developing a new range-topping diesel engine to take on Volkswagen’s 5.0-litre V10 (above), as used in the Touareg and Phaeton. The 6.0-litre V12 is based around the German car maker’s advanced new 3.0-litre V6 diesel. Autocar sources say the two engines share the same basic architecture, major components and bore-centre measurements, although full details won’t be made official until mid-2006 when it is planned to power selected new Mercedes models.
Already undergoing extensive durability testing, the new V12 common-rail diesel is said to use a combination of piezo injectors and twin turbochargers to produce 360bhp and a mighty 686lb ft of torque — figures that would make it the world’s most powerful passenger-car diesel engine by a considerable margin.
Among the models destined to receive Mercedes’ super diesel are the new G-, M-, R- and S-class. There’s also an outside chance it could appear underneath the bonnet of the Maybach luxury saloon (right).
Up until now Mercedes’ largest diesel engine has been a 4.0-litre V8 which delivers 256bhp and 413lb ft. It is planned to be replaced by a new 4.4-litre V8 with over 300bhp and 516lb ft by the end of 2005.