AMG breaks the 300kW ceiling for 2.0-litre production engines.

Since its first turbocharged 2.0-litre four-cylinder, the M133, AMG has set new power output standards for this specific size and configuration of production engine.

When it debuted in 2013, the A45’s 2.0-litre turbocharged ‘four was good for 265 kW – notably more powerful than any other similarly sized production engine. AMG has just revealed its latest evolution of the boosted 2-litre four-cylinder engine architecture, and the numbers are astonishing.

Under the AMG engine codename of M139, this new 2.0-litre engine produces 310 kW and 500 Nm. The number which truly contextualises its potency is that this new AMG engine delivers 155 kW per litre, more than most production superbikes.

Overall displacement is 1991 cc and the internal architecture is radically undersquare, featuring an 83 mm bore versus 92 mm of stroke.

A single twin-scroll turbocharger runs on a roller-bearing compressor and turbine wheels, to eliminate inertia, and boost pressure is 2.1 bar. The M139 engine’s turbo can spin to an amazing 169000 rpm.

Reduction friction comes courtesy ofnanoslide cylinder coatings, a technology developed by the Mercedes F1 team, whilst 2 mm larger exhaust valves help better feed the turbo and clear the combustion chamber. As a result, this engine can run a 7 200 rpm maximum crank speed – which is credibly high for a long-stroke turbocharged engine.

AMG’s third-generation fuelling system produces 200-bar of direct injection pressure and the entire M139 engine only weighs 160 kg, thanks in part to a new aluminium crankcase.

This amazing 2.0-litre engine will become available in AMG’s next wave of 45-Series models, due later this year, and customers will have the option of two states of tune: either the full-power ‘S’ version detailed above, or a 285 kW/480 Nm application. South Africa is a notable 'S' only country though, so expect maximum power derivatives to be available.

Watch the new 2.0-litre turbocharged AMG engine being built