The 4.6-liter V8 twin-turbocharged Mercedes M278 engine was introduced in 2010 as a replacement for the well-known M273 engine under the hood of the popular E, S and GL class models. The power unit is offered only in one volume, but in different degrees of forcing.
The V8-family includes: M113 E43, M113 E50, M113 E55, M119 E42, M119 E50, M119 E60, M156, M157, M177, M273, M278.
Specifications
| Production years | since 2010 |
| Displacement, cc | 4663 |
| Fuel system | direct injection CGI |
| Power output, hp | 367 – 408 (M 278 DE 46 AL red.) 435 – 455 (M 278 DE 46 AL) |
| Torque output, Nm | 550 – 600 (M 278 DE 46 AL red.) 700 (M 278 DE 46 AL) |
| Cylinder block | aluminum V8 |
| Block head | aluminum 32v |
| Cylinder bore, mm | 92.9 |
| Piston stroke, mm | 86 |
| Compression ratio | 10.5 |
| Features | Bi-Turbo |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | yes |
| Turbocharging | two Garrett MGT1752SM |
| Recommended engine oil | 0W-40 |
| Engine oil capacity, liter | 8.5 |
| Fuel type | petrol |
| Euro standards | EURO 5/6 |
| Fuel consumption, L/100 km (for Mercedes CLS 500 2012) — city — highway — combined |
12.5 6.9 9.0 |
| Engine lifespan, km | ~300 000 |
| Weight, kg | 220 |
The engine was installed on:
- Mercedes CL-Class C216 in 2010 – 2014; CL-Class C217 in 2014 – 2017;
- Mercedes CLS-Class W218 in 2011 – 2018;
- Mercedes E-Class W212 in 2011 – 2016;
- Mercedes GL-Class X166 in 2012 – 2015;
- Mercedes GLE-Class W166 in 2015 – 2018;
- Mercedes GLS-Class X166 in 2015 – 2019;
- Mercedes ML-Class W166 in 2012 – 2015;
- Mercedes S-Class W221 in 2011 – 2013; S-Class W222 in 2013 – 2017;
- Mercedes SL-Class R231 in 2012 – 2020.
Disadvantages of the M278 DE46 engine
- Due to the design features of the motor, the timing chain tensioners quickly fail.
- If you do not pay attention to knocks, you will have to replace the entire timing with phase regulators.
- The oil pump has low reliability, which leads to scuffing and overhaul.
- Alusil coating of the cylinder walls does not tolerate detonation, and the engine is prone to it.
- Piezoceramic nozzles are afraid of overheating and rarely survive even up to 100,000 km.
