This engine is begging for a lightweight coupe.

Entirely assembled by hand, AMG’s new M139 engine comes to life at home in Affalterbach where Mercedes was kind enough to shoot a video with the 2.0-litre engine. It will equip the next generation of “45” cars, which will include new arrivals such as the A45 Saloon and the GLB45 joining the A45, CLA45, and CLA45 Shooting Brake.

Much like the V8 AMGs are available in a two-tier offering, there will be base and flagship S versions of the world’s most powerful four-cylinder engine to be installed in a series production car. The M139 has been engineered to produce 382 bhp and 354 lb-ft in standard configuration and a mighty impressive 416 hp and 369 lb-ft in S guise.

The M139 has more power than Audi Sport’s larger 2.5-litre inline-five rated at 400 bhp 354 lb-ft, but less than the 2014 Mitsubishi Lancer Evolution X FQ-440 MR with its 440 bhp and 412 lb-ft. However, that doesn’t count as a regular production car since only 40 cars were built and all were sold in the U.K.

Mercedes-Benz A-Class Coupe
Mercedes-Benz Vision SLA concept 2000
Mercedes-Benz Vision SLA concept 2000

Getting back to the AMG engine at hand, in an ideal world, this would also power a coupe as a lightweight and more exciting alternative to the four-door 45 models. An A-Class Coupe like the one speculatively rendered above would be nice, but it’s just wishful thinking at this point. Mercedes did have a similar thought back in 2000 with the Vision SLA, a small front-wheel-drive-based roadster concept with only two seats.

In 2014, rumours of a sub-SLK model in the same spirit as the SLA emerged, but nothing happened. With AMG about to offer 400+ bhp in several FWD-based models, an SLA Coupe would be the cherry on top of the company’s compact car range.

Video: Mercedes-Benz

Gallery: Mercedes-AMG M139 four-cylinder engine