Pop quiz: what’s the most powerful production 2.0-liter 4-cylinder engine? If you think it’s something from Japan likes Subaru or Honda, think again. The answer is Mercedes-Benz.

In its highest form of tune, the 2.0-liter M 139 produces, get this: 421 horsepower while its torque is a stagger 500 Nm. This means the diminutive engine, built in Affalterbach by Mercedes-AMG produces 211 horsepower per liter—ranking ahead of many well-known supercar engines.

Apart from its performance figures, this new engine is “torque shaped” by its engineers to develop its peak torque at an accessible 5,000 to 5,250 rpm range, while its maximum redline is maintained at 7,200 rpm—similar to a normally-aspirated engine.

The M 139 2.0-liter engine features some ingenious designs that help it produce such staggering figures such as being a closed deck design, rotated around the vertical axis by 180 degrees for improved air flow; a twin scroll turbo with parallel flow passages; an electronically controlled waste gate with 2.1 bars (30.4 PSI) of pressure; coated pistons and cylinders (the same one used in their Formula One cars); and two-stage fuel injection.

Mercedes-AMG M 139 2.0-liter 4-Cylinder Specifications:

• Displacement: 1,991 cc
• Bore x Stroke: 83.0 x 92.0 mm
• Output: 421 horsepower @ 6,750 rpm / 387 horsepower @ 6,500 rpm
• Torque: 500 Nm @ 5,000-5,250 rpm / 480 Nm @ 4,750-5,000 rpm
• Max Engine Speed: 7,200 rpm
• Compression Ratio: 9.0:1
• Engine Weight: 160.5 kilograms