The Mercedes-Benz OM 654 is a family of inline-four cylinder automobile diesel engines introduced by Mercedes-Benz in 2016. This is one of the most powerful 2-liter inline-4 cylinder diesel engines with a single twin-scroll turbocharger.^[2]

The engine is a 2.0 litres (1,950 cc) turbo-diesel cast aluminum block, inline four-cylinder with balancing shafts.^[3] It has a single turbo and its cylinder walls are lined with slippery Nanoslide, an iron-carbon coating that cuts friction. In the 200-configuration it produces 110 kW (150 PS; 148 hp) at 4,500 rpm with peak torque of 320 N⋅m (236 lbf⋅ft) at 1,400-3,200 rpm. In the 220-configuration it produces 143 kW (194 PS; 192 hp) at 3,800 rpm with peak torque of 400 N⋅m (295 lbf⋅ft) at 1,600-2,400 rpm. The engine weight is 168.4 kg (371 lb) (a 17% improvement over the 202.8 kg (447 lb) of the previous 2.1 litres (2,143 cc) OM651).^[4][5] Also, the engine consumes 13% less fuel than its predecessor. It is planned that it will feature across the entire Mercedes-Benz range of cars and vans. Both the 200d and 220d are mated to a 9 speed dual clutch transmission developed by Mercedes Benz.

It is a version of OM 654 placed transversely (quer). This makes it possible to mount this engine in smaller models of cars and front-wheel-drive vehicles.^[6][7]

With the OM 654 M, Mercedes claims to deliver the worldwide first diesel engine with integrated starter generator. The revised two-liter turbodiesel four-cylinder was given a new crankshaft for electrification, increasing the displacement by 43 to 1,993 cubic centimeters. At the same time, the injection pressure will be increased from 2,500 to 2,700 bar. The maximum power is now 265 hp, the maximum torque 550 Newton meters. On the exhaust side, a NOX storage catalytic converter, particle filter and two SCR catalytic converters have been retrofitted.