THE BREAKDOWN:
- Mercedes-Benz will replace the SL’s four-cylinder engine with a straight-six unit.
- The automaker is making the switch to meet stricter emissions regulations.
- The new SL53 will allegedly arrive with the car’s facelift in 2027.
Mercedes-Benz is reportedly making a big change to the entry-level SL. With its upcoming 2027 facelift, the automaker will replace the current car's four-cylinder engine with a six-cylinder one.
According to a new Auto Motor Und Sport report, Mercedes will discontinue the M139 engine that powers the SL43 because it does not meet Euro 7 emissions standards. The automaker will allegedly replace it with the M256 Evo, the 3.0-liter inline-six mild-hybrid engine, and call it the AMG SL53.
The new engine will supposedly produce 449 horsepower and be supplemented by a 23-hp integrated starter-generator. The SL53 will also come standard with all-wheel drive, unlike the SL43, which was rear-wheel drive.
The SL's V8
The report also says Mercedes will tweak the V8 that powers the SL55 and SL63. The twin-turbocharged 4.0-liter engine will switch from a cross-plane crank to a flat-plane crank, increasing performance while still meeting the new emissions regulations.
The engine will produce 537 hp in the SL55 and an astounding 650 hp in the SL63. The current 55 makes 469 horsepower and 516 lb-ft, while the 63 would see a significant increase, jumping from 577 hp to 650 hp.
The report offered no details about the SL63 S E Performance plug-in hybrid, which pairs the V8 to an electric motor. It makes 805 hp, but the new V8 could push that over 880 hp, we hope.
Gallery: 2023 Mercedes-AMG SL43 First Drive
Motor1’s Take: This might be one of the few times that emissions regulations benefit enthusiasts. Mercedes must update its powertrain lineup, and as a result, buyers get a better engine in the entry-level offering and more power at the top end. That’s a win-win.
