Mercedes-Benz has decided to discontinue tests on range-extender drivetrains for its electric cars, according to a source familiar with the company’s car development activities. Range-extender technology involves using a combustion engine as a generator to charge the battery when it runs low. Despite beginning an advanced engineering program, Mercedes-Benz has chosen to focus on simpler and more cost-effective battery-electric drivetrains instead. The decision was made based on the conclusion that range-extender drivetrains have limited long-term sales benefits and high production costs.
One of the range-extender prototypes developed by Mercedes-Benz is based on the EQS model. It features a front-mounted turbocharged 1.0-liter two-cylinder engine that acts solely as a generator without directly driving the wheels. The compact petrol engine is modified with Miller-cycle thermodynamic prototypes to improve constant-rev efficiency. The prototype also includes a rear-mounted electric motor and a floor-mounted lithium-ion battery for power delivery.
The petrol engine in the Mercedes prototype is combined with a fuel tank of unspecified capacity, giving it a theoretical range beyond the 487 miles of the rear-driven EQS 450+. This range-extender setup allows the vehicle to generate electricity as a backup in situations where plug-in charging is not available or possible.
The decision by Mercedes-Benz to discontinue range-extender drivetrains comes as attention has turned to these types of electric vehicles, particularly in China. In response to the lack of EV charging infrastructure in second- and third-tier cities, many Chinese automakers have begun offering range-extender options alongside pure-electric drivetrains in selected models. For example, Li Auto, a Beijing-based company, sold 376,030 vehicles in 2023, all featuring range-extender drivetrains. These drivetrains help alleviate range anxiety and provide an alternative to plug-in charging in regions where suitable charging infrastructure is lacking.
Overall, Mercedes-Benz’s shift away from range-extender drivetrains highlights the company’s commitment to simplifying and cost-effectively improving its electric vehicles. By focusing on battery-electric drivetrains, Mercedes-Benz aims to provide customers with more accessible and efficient electric cars. This decision also reflects the growing demand for pure-electric drivetrains and the need for a robust charging infrastructure to support widespread adoption of electric vehicles.
