Star Assembly, a 100% Mercedes-owned subsidiary and manufacturer of gearboxes, has started production of electric motors for the new Mercedes CLA EQ and Mercedes GLC EQ models at its plant in Sebeș, Romania. Beginning in 2026, the plant will also produce electric motors for the upcoming Mercedes C-Class EQ.
The Star Assembly plant, fully owned by Mercedes and located in Sebeș, western Romania, has become the second facility in the world to produce electric motors for Mercedes’ new generation of electric models.
Currently, Star Assembly manufactures the electric motors for the new Mercedes CLA and recently began producing motors for the future Mercedes GLC EQ — which was unveiled at the Munich Auto Show and will go into production in 2026 at the Bremen plant in Germany.
Starting in 2026, Star Assembly will also supply the motors for the first all-electric Mercedes C-Class, which will be built in Kecskemét, Hungary.
To support electric motor production, Mercedes built a new manufacturing facility covering an area of 30,000 square meters — 15,000 of which are dedicated to the production line itself. The production line stretches 1,000 meters long and includes 200 manual and automated workstations.
All workers at the Star Assembly plant have been reassigned from other departments within the company.
The propulsion system of the new Mercedes GLC EQ was developed in-house by Mercedes and consists of three main components: the electric motor, power electronics, and transmission. The assembly of these components takes place at the Sebeș plant.
The Sebeș factory is integrated into Mercedes’ MO360 digital production system. The plant is powered entirely by renewable energy sources, and a photovoltaic park with a capacity of up to 5 MW is currently being installed. The facility also uses heat pump-based heating.
At the inauguration ceremony for the new electric motor production line for the Mercedes GLC EQ, Romanian Prime Minister Ilie Bolojan stated:
“The investments of Mercedes-Benz mean technology transfer, access to markets, jobs, and integration of Romanian industry into the European value chain, which lays the foundation for an economy that will generate healthy development for the future. When a company comes to a location, it’s not only about production itself. It also means supporting education and social responsibility. To be a competitive country means to have a qualified workforce. I want to thank and congratulate the team at Star Assembly Sebeș for their significant contribution.”
Star Transmission (STC) was founded in 2001 as a joint venture between Daimler and the mechanical enterprise in Cugir. It was established as a production line for gears and transmission shafts for Mercedes gearboxes. Collaboration between the two companies actually began earlier, in 1996, when the Cugir Mechanical Plant won a contract from Mercedes to produce gears for the first-generation A-Class gearbox.
Star Transmission became a wholly owned Daimler subsidiary in 2013, the same year the Star Assembly division and factory were established in Sebeș. Also in 2013, Star Transmission began production of the 5-speed automatic gearbox for Mercedes commercial vehicles in a 9,000-square-meter facility employing 1,000 workers.
In 2014, the plant was expanded with another 13,000-square-meter hall, and the workforce grew from nearly 200 to 1,200 employees. The new hall housed production of the 7-speed dual-clutch gearbox for Mercedes’ compact range (A, B, CLA, CLA Shooting Brake, and GLA).
In April 2016, the factory began assembling the new 9G-Tronic 9-speed automatic gearbox with a torque converter, now used in all Mercedes models with rear-wheel drive and in 4Matic variants derived from the same platform.
In February 2019, production began for the 8-speed dual-clutch automatic transmissions intended for models in the compact range.
