When Mercedes announced its new turbocharged 2.0-litre engine, it did so with the proclamation it was the most powerful four-cylinder engine ever. We had to dig to confirm Mercedes’ assertion, and all we could find was the Mitsubishi Lancer Evolution FX-440 MR that made 440 bhp from its 2.0-litre four-cylinder engine – 24 more than the Mercedes. However, the company only made 40 examples for the UK. But according to Mercedes-AMG’s head of engine development Ralph Illenberger, who spoke with Carsales, an even more powerful version is possible.
Illenberger said the engine has yet to reach its peak performance, adding that there’s more to come with room for improvement. However, he said it was a challenge to bring the current 2.0-litre mill to a street-legal car. He concluded by saying, “We’ll see what the future will bring.”
Gallery: Mercedes-AMG M139 four-cylinder engine
Right now, Mercedes offers the M139 engine in two performance flavours – standard and S. The higher powered S makes 416 bhp and 369 pound-feet of torque. The standard M139 mill produces 382 bhp and 354 lb-ft of torque. Adding a third tune doesn’t seem too outside the realm of possibility. Both versions of the engine use a twin-scroll turbocharger with the S engine producing up to 30.5 psi (2.1 bar) of boost while the standard engine makes up to 27.6 psi (1.9 bar).
The engine will find its way into the Mercedes-AMG A45 and the CLA 45 saloon. Spy photos hint the engine could end up in the GLB-Class crossover, too. If Mercedes wrings more power out of its 2.0-litre engine, it may keep the little engine at the top of the most potential four-pot mills. Then again, no reign lasts forever.