“No Thanks, BMW”: How Mercedes Reinvents Its Engine Playbook and Dismisses the Bavarian Rumor Mill

In the luxury automotive world, rumors of radical partnerships always stir the market. When whisperings recently claimed Mercedes-Benz might borrow BMW engines for its next generation of models, shock waves zipped through both camps of loyalists and rival engineers alike. As electrification and cost pressures make the industry more unpredictable than ever, such a move wouldn’t just be historic—it would upend the longstanding notion of brand purity. But, according to the top tech minds at Mercedes, those wild headlines are fiction. Here’s why Stuttgart’s star isn’t about to borrow Bavarian brains, and how Mercedes is doubling down on in-house innovation for its future lineup.

The Tale of Two Rivals

Long ago, in the heart of Germany, two automotive giants carved their legacies out of steel and speed. For decades, BMW and Mercedes-Benz competed fiercely for the affections of drivers seeking dynamic performance and elegant comfort. In the fabled halls of each, engineers joked about the other’s quirks and swore only their own hands could tune a proper engine. Yet as the road ahead shifted toward hybrids and EVs, even loyalists wondered—could the two ever cross wrenches for mutual gain?

The Partnership That Wasn’t

Summer 2025 saw major German outlets speculate that Mercedes was considering a partnership with BMW to share engines and transmissions, especially as both brands eyed the bumpy road to full electrification. The headline-grabber? Mercedes was said to be planning to use BMW’s renowned turbocharged 2.0-liter four-cylinder in mainstream models to pare back development expenses. Some claimed deals were so advanced that BMW-powered Mercedes sedans would roll out as soon as 2027.

Mercedes Responds: “Absolutely Not”

Speaking on the record with Motor1 at the Munich Motor Show, Mercedes CTO Markus Schaefer pulled no punches: “There is no truth to this.” He explained that Mercedes had already developed a versatile new modular engine family—FAME (Family of Modular Engines)—that’s ready to power both hybrid and conventional models across the lineup. Schaefer’s message to rumor-mongers and competitors was simple: the three-pointed star won’t cede engine pride to anyone.

Key Details On Mercedes’ FAME Engines

• FAME modular family covers all displacements—futureproofed for global markets.

• Already designed to meet EU7, China 7, and upcoming US emissions regulations.

• New CLA features in-house Mercedes four-cylinder hybrid.

• MMA platform (Modular Mercedes Architecture) will spread FAME tech across multiple models.

• Boosted by integrated 48V mild-hybrid systems for efficiency.

Technical Spotlight: The M 252 Hybrid Four-Cylinder

• Turbocharged 1.5-liter inline-four (M 252)

• Paired with 8-speed dual-clutch automatic

• Integrated electric motor

• 48V lithium-ion battery (1.3 kWh)

• Output: 188 hp (US spec)

Why Mercedes Says “Nein” to BMW Engines

• Maintains unique brand engineering and performance DNA

• Protects Mercedes’ technical sovereignty

• Modular engine family allows more flexible global rollout

• Enhanced emissions compliance, especially for China and Europe

• In-house hybrids allow faster integration of advanced tech

Comparison Table: Mercedes FAME vs BMW B48 Engine

Why Engine Sharing Was Believable—But Unlikely

Big-name automakers now routinely share EV, transmission, and software platforms—from Toyota and Subaru to Stellantis collaborations. As R&D costs soar, even archrivals sometimes pool resources in battery or autonomous tech. But engine sharing is an even trickier negotiation, as it affects sound, character, and driving identity—core attributes for brands like Mercedes.

While partnerships define much of the modern car industry, Mercedes-Benz won’t be installing BMW engines anytime soon. By doubling down on its new FAME engine family and stepping up hybrid integration, Mercedes maintains full control of its legacy and future—even as electrified rivals close in. For faithful buyers, that means the spirit of Stuttgart will continue to power each new model—not the heart of Munich, no matter what rumors may say.