The world’s most powerful 2.0 litre, four-cylinder series production engine has been revealed by Mercedes AMG, set to feature in its upcoming ’45’ model range.
Developing 415bhp in its most potent ‘S’ form, this completely new 2.0 turbo replaces the engine in used in the previous A45 A-Class, CLA45 and GLA45
Another major aim has been extracting a sportier driving experience from the engine by altering its torque delivery. While the previous, M133 four-cylinder engine’s torque curve resembled a diesel’s, rising steeply to level off across a wide chunk of the rev range, the new M139 2.0 produces more of a crescendo of thrust.
The aim is to produce the rising rush of acceleration characteristic of a revvy, normally aspirated engine. Rather than flat-lining, diesel-style, from around 2000rpm, AMG’s new engine generates peak torque at 5200rpm, while nevertheless producing more shove than the old one between 1000-2000rpm, the strongest surge developing from 3000rpm. Overall, said Illenberger, “it produces a more sporty delivery”.
The transmission shares the engine’s cooling circuit and has its own heat exchanger mounted directly to it. Also interesting is the fact that the engine is oriented 180 degrees opposite its predecessor with the exhaust manifold and turbo facing the firewall. This apparently helps reduce the complex turns needed for intake and exhaust piping, and that presumably also improves gas flow. And like all of AMG’s big V8s, each engine is assembled by one person’s hands.