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.
Mercedes V8 family: M113 E43, M113 E50, M113 E55, M119 E42, M119 E50, M119 E60, M156, M157, M176, 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.
Frequently asked questions about the Mercedes M278 DE46
How much power does the Mercedes M278 DE46 make?
Power output of the Mercedes M278 DE46, hp: 367 - 408 (M 278 DE 46 AL red.); 435 - 455 (M 278 DE 46 AL). Torque, Nm: 550 - 600 (M 278 DE 46 AL red.); 700 (M 278 DE 46 AL).
How much oil does the Mercedes M278 DE46 take and which one?
Engine oil capacity: 8.5 liters. Recommended oil: 0W-40.
Does the Mercedes M278 DE46 have a timing belt or chain?
The Mercedes M278 DE46 uses a timing chain.
Is the Mercedes M278 DE46 turbocharged?
Yes, the Mercedes M278 DE46 is turbocharged (two Garrett MGT1752SM).
Does the Mercedes M278 DE46 need valve clearance adjustment?
No, the Mercedes M278 DE46 has hydraulic lifters, so the valve clearances do not need to be adjusted.
How long does the Mercedes M278 DE46 last?
The typical lifespan of the Mercedes M278 DE46 is ~300 000 km with proper maintenance.
What is the fuel consumption of the Mercedes M278 DE46?
Mercedes CLS 500 2012: city 12.5, highway 6.9, combined 9.0 L/100 km.
What cars was the Mercedes M278 DE46 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 and 3 more (see the full list above).
What are the common problems of the Mercedes M278 DE46?
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. All known problems.
