Mercedes-Benz Reveals Full Details of New BEV and Mild Hybrid CLA Powertrains

Hard on the heels of Mercedes-Benz’s electric-vehicle distance record using a third-generation Concept CLA test mule, the automaker releases more details of its upcoming electric and mild hybrid powertrains.

Battery-electric vehicle power comes with its electric drive unit to be used in the dedicated electric platform Mercedes-Benz modular architecture forming the next generation drive units.

Its 800V technology and silicon carbide (SiC) inverter moves from the VISION EQXX to the compact class. This 268-hp drive unit features a permanently excited synchronous motor on the rear axle and was developed entirely in-house by Mercedes-Benz engineers.

In addition, the 4MATIC models have an 107-hp drive unit on the front axle, also equipped with a SiC inverter and a top speed of 130 mph (209 km/h) is claimed.

The system targets a WLTP range of more than 466 miles (750 km) with a claimed battery-to-wheel efficiency of 93% on long trips.

This will be coupled to a 2-speed gearbox on the main drive at the rear axle, boosting efficiency and claiming highly dynamic driving performance.

The 85-kWh battery pack claims DC fast charging of up to 320 kW and, in the Concept CLA Class, a 10-minute charge can add a range of up to 186 miles (300 km).

Its cells have anodes in which silicon oxide is added to the graphite. Compared to the previous battery with conventional graphite anodes, the energy density is upped by 20%.

To mitigate against the chances of battery damage and potential fires the battery housing is integrated into the vehicle’s structure and crash safety system.

Mercedes-Benz says it has taken comprehensive precautions to prevent thermal runaway with technical solutions for the new battery generation.

Hybrid Technology

Following the BEV’s initial launch, the automaker will bring a new 48V mild hybrid system to market using a 26-hp electric motor coupled to a turbocharged 1.5L gasoline 4-cyl. producing a total maximum system output for the U.S. version of 188 hp.

The system claims its energy recuperation function aids the vehicle's ability to drive emission-free in urban environments, plus the ability to drive up to 62 mph (100 km) on electric power alone.

The gasoline engine, code named M 252, belongs to Mercedes-Benz’s FAME (Family of Modular Engines) family designed for a wide range of vehicle applications.

Common features include an all-aluminum crankcase with Nanoslide technology, a cylinder head with partially integrated manifold and a turbocharger with segment turbine with switchable scroll connection. Other highlights include the compact charge airduct and the exhaust system positioned close to the engine in 1-box design, which is prepared for future exhaust emission standards.

The gasoline engine uses a combustion process based on the Miller cycle to reduce fuel consumption especially in the partial load range during everyday use. The comparatively early closing of the intake valves reduces throttle losses and enables a high compression ratio of 12:1.

Both the electric motor and inverter are integrated into a new electrified 8-speed dual-clutch transmission.

In-cabin climate control is handled by an electric refrigerant compressor which reduces frictional power and cools the interior even when stationary and in all-electric operation.

Consumers will have the choice between front-wheel drive and 4MATIC all-wheel drive.