Mercedes-Benz / AMG
M 152, M 157, M 278
Manufacturer:	Mercedes-Benz / AMG
Production period:	since 2010
Style:	V , eight-cylinder
Engines:	4.7 liters (4663 cc)  5.5 liters (5461 cc)
Previous model:	M 156 / M 159 , M 273
Successor:	M 176 / M 177 / M 178
Similar models:	M 276

The Mercedes-Benz M 278 is an engine series from Mercedes-Benz, and the successor to the M 273 generation. It is an 8-cylinder V- engine . In contrast to the equally new six-cylinder M 276 , the cylinder bank angle remained at 90 °, although the engines are closely related.

Compared to its predecessor, the engines are significantly more economical and powerful, among other things by gasoline direct injection . In addition, intelligent generator management and a demand-controlled engine oil pump, fully variable injection pressure of 100 to 200 bar, twin turbochargers with air-water charge air cooling, exhaust gas turbocharger with wastegate valves, new cast pistons and engine electronics with Controlled Efficiency stop-start function. Power is transmitted via the 7- speed automatic transmission or the AMG SPEEDSHIFT MCT 7-speed sports transmission.

The introduction of the engines took place gradually in autumn 2010, starting with the S-Class (Type 221) and the CL-Class (Type 216). The AMG variant is given the designation M 157 for the turbo-charged variant or M 152 for the vacuum variant with cylinder deactivation .

Variants

The new eight-cylinder replace the previous 500 and 63 AMG. They are available in two displacement levels:

M 152 DE 55 

M 157 DE 55 AL 

M 278 DE 46 AL red. 

M 278 DE 46 AL 

The basic version of the M 278 in the E-Class, CLS, S-Class and CL was again available with 4MATIC all - wheel drive. From 2011 to 2016 he was also installed in the E-Class . The S 450 with the M 273 engine was not offered in autumn 2010; Since summer 2017 there is again a S 450 in the class 222 , here however with the new straight-six M 256 .