Mercedes-Benz is preparing a new range of four-cylinder diesel engines that will be installed in various models later this year, including the C-class. Codenamed OM651, the new 2143cc unit uses twin turbochargers, a common-rail injection system and 16.2:1 compression ratio to provide up to 20 per cent more power and fuel savings of up to 25 per cent over the engine it replaces, the OM646.Three distinct versions of the OM651 are planned. In range-topping form, set to find its way into a new C250 CDI model that will go on sale in the UK in October, it kicks out a solid 201bhp and 369lb ft of torque while providing Mercedes’ executive-class saloon with a 0-62mph time of 7.7sec, combined fuel consumption of 52.3mpg and a CO2 rating of 143g/km.The C250 CDI will be joined this autumn by a mid-range version of the new diesel packing 168bhp and 295lb ft in a follow-up to today’s C220 CDI, and a base C200 CDI variant running a single turbocharger and producing 134bhp and 243lb ft.Following its appearance in the C-class, the new engine should feature in the next-generation E-class and upcoming, BMW X3-challenging GLK off-roader, which goes on sale (but not I the UK) next March.
