Mercedes-Benz OM651 engine
| Mercedes-Benz OM651 | |
|---|---|
| Overview | |
| Manufacturer | Daimler-Benz |
| Production | 2008-present |
| Combustion chamber | |
| Configuration | I4[1] |
| Displacement | 2,143 cc |
| Cylinder block alloy | iron |
| Cylinder head alloy | aluminium |
| Valvetrain | DOHC 16-valve |
| Compression ratio | 16.2:1 |
| Combustion | |
| Turbocharger | turbo/twin-turbo |
| Fuel system | common rail with piezo injectors at 2000 bars |
| Fuel type | diesel |
| Cooling system | intercooler |
| Output | |
| Power output | 120-208 ps |
| Torque output | 300-500 Nm |
| Chronology | |
| Predecessor | OM646 |
| Successor | TBA |
The OM651 engine family is an inline-four cylinder Diesel automobile engine from Mercedes-Benz introduced in 2008. The chief design goal was to create a common engine platform that maximized the part commonality between the engines manufactured by Daimler. One requirement of the design was its ability to be mounted in both longitudinal and transverse fitments. Emission standards and fuel efficiency were also driving design factors. The engine uses recirculated exhaust gas to reduce the oxygen in the cylinders to "starve" any reactions that would produce NO(x), enabling it to meet Euro 5 emission standards.
Although all engines have the same 2,143 cc swept volume, various outputs are produced ranging from 120 ps (badged x180) to 204 ps (badged x250) with the 170 ps (x220) and 204 ps versions employing a twin-turbo system with a small, high pressure turbo charger enabling it to boost quickly at the low RPM, as well as a large, lower pressure turbo that improves performance at higher RPM. Lower output versions have only a single turbocharger. Directly controlled piezo-electric fuel injectors are used allowing higher fuel pressure levels to be used than in previous engines in the aim of increasing combustion efficiency.