The new Mercedes-Benz CLA will be revealed in the coming months with the choice of two battery-electric powertrains or an all-new petrol engine that promises diesel levels of efficiency.
The first car on Mercedes‘s new MMA platform has been engineered as an EV first, with heavy technical and design influence from the record-breaking EQXX concept, but in recognition that “the wishes and mobility needs of customers in different regions determined the pace” of the switch to EVs, it will also be offered with a bespoke mild hybrid powertrain engineered with a stringent focus on efficiency.
Inside Mercedes’s new diesel-baiting petrol MHEV
The CLA’s new ‘M252’ 1.5-litre four-cylinder has been designed to be as small as possible, because MMA is an EV-native architecture so it has to take up not much more space than the electric car’s front motor. It is, though, described as modular in its construction, with the general design able to be scaled up for larger applications.
The cylinders are positioned as close together as possible to keep the block compact, the exhaust manifolds are housed within the cylinder head itself rather than outside it, while the gearbox, electric motor and inverter are all integrated into one tightly formed unit.
All in, the motor is said to be smaller in every dimension and some 17% lighter than Mercedes’s current four-cylinder engine.
A four-pot was chosen over a triple because of the heightened refinement offered by an even number of cylinders. A comprehensive array of insulation measures including foams and covers have been installed to further mitigate unwanted noise and vibration to a minimum.
The engine will send 134bhp or 161bhp through the front axle, or 188bhp to both ends in the range-topping CLA 4Matic – which Mercedes notes is a “considerable output per litre”.
Indeed, this will be among the most potent engines of its size. For reference, the same-sized four-pot in the Mini Cooper C produces 154bhp, and the 1.5 in the Volkswagen Golf is capped at a 148bhp maximum.