Mercedes-Benz offers drivetrain choice – electric and hybrid

Mercedes-Benz is providing electric or hybrid choices in upcoming CLA vehicle architecture.

The brand says the technology offensive is being launched with the Mercedes-Benz Modular Architecture (MMA) bringing the Vision EQXX technologies to the compact class.

The new electric CLA is the first model to be based on the MMA, says Mercedes-Benz, adding the CLA will also be offered as an economical hybrid.

The new CLA is the first example of intelligent modularity in the upper compact segment, it says.

The company is now incorporating the findings from its project into series-production vehicles.

“The centrepiece of this versatile and flexible vehicle architecture is the so-called skateboard chassis, a floor assembly designed primarily for electric cars, including the corresponding drive and chassis components,” says Mercedes-Benz.

“The body design varies, however.

“In the newly defined entry-level segment, Mercedes-Benz is planning a family of four models in total. In addition to the CLA as a four-door saloon, these include a shooting brake and two SUVs.

“Our new hybrid drive with electric transmission is also setting new standards in terms of efficiency.”

Mercedes-Benz Group AG management board member, development and procurement chief technology officer Markus Schäfer says the company will also rely on intelligent modularity with a scalable skateboard design for future model families in other segments.

“Because Mercedes-Benz is striving for a leading role in both electric driving and vehicle software, the company has massively increased its development activities in these areas.”

This includes the recent opening of the eCampus in Stuttgart-Untertürkheim as a competence centre for the development of cells and batteries for the brand’s future EVs.

The aim is to develop innovative chemical combinations and optimised production processes for high-performance cells with ‘Mercedes-Benz DNA’ and thus reduce battery costs by more than 30% in coming years, says the brand.

The electric drive unit (EDU 2.0) is the first of a new generation of electric drive units from Mercedes-Benz and the highly integrated units form an intelligent modular system, it says.

With the main drive on the rear axle for optimum traction and driving characteristics, Mercedes‑Benz is now introducing a drive layout familiar from the mid-size and luxury classes to the entry-level segment.

The 200kW electric drive unit with a permanently excited synchronous machine (PSM) on the rear axle was developed by Mercedes-Benz engineers.

The high-performance power electronics are equipped with a silicon carbide (SiC) inverter for particularly efficient energy utilisation, it says.

“The EDU 2.0 reconciles the conflicting goals of maximum torque, top speed and exemplary efficiency, especially in real driving conditions.”

The 4MATIC models also have an 80kW drive unit on the front axle equipped with a next-generation inverter with SiC and designed as a PSM. The front electric motor acts as a “boost” drive and is only switched on when the corresponding power or traction is required.

This task is performed by the disconnect unit (DCU), which Mercedes-Benz is now using in the entry-level segment.

“The DCU can decouple the electric motor on the front axle at lightning speed when the load is low, so that the electric motor and parts of the transmission are at a standstill.

“This reduces front axle losses by 90% and increases the range.

“In the case of the Concept CLA Class, this would correspond to a range of more than 750km (WLTP),” says Mercedes-Benz.

“With an energy consumption of just 12kWh/100km, the Concept CLA Class would be the ‘one-litre car’ of the electric age.”

Mercedes-Benz says 800-volt architecture maximises efficiency and performance and, in conjunction with the new battery generation, can significantly reduce charging time.

Within 10 minutes, a range of up to 300km can be added to the Concept CLA Class using DC fast charging.

Customers will be able to choose between batteries with two different cell chemistries, says Mercedes-Benz.

“The cells of the premium version with a usable energy content totalling 85kWh have anodes in which silicon oxide is added to the graphite.

“Compared to the predecessor battery with conventional graphite anodes, the gravimetric energy density is up to 20% higher.

“At cell level, the volumetric energy density of the cell chemistry is 680Wh/l,” says Mercedes-Benz, adding the proportion of cobalt has been further reduced.

An electric entry-level variant has a lithium iron phosphate (LFP) cathode battery. Its usable energy content is 58kWh and the volumetric energy density of the cell chemistry is 450Wh/l, says the brand, adding the new hybrid is capable of all-electric driving too.

“The electric motor with 20kW drive power has been integrated into a new electrified eight-speed dual-clutch transmission (8F-eDCT) together with an inverter. The electrical energy of up to 1.3kWh is provided by a new 48-volt battery with lithium-ion technology and a flat-pack design.

“Thanks to energy recuperation and all-electric driving capability at urban speeds, this drivetrain is particularly efficient.

“This is enhanced by electric coasting at a speed of up to around 100km/h,” says Mercedes-Benz.

“The combustion engine is a new FAME (Family of Modular Engines) four-cylinder petrol engine. The hybrid drivetrain is initially available in three power levels with 100, 120 or 140kW.”