Mercedes M278 Engine

The M278 Engine is a descendant of the company’s earlier M273 V8 engine, which also had an aluminum engine block and low-friction Silitec aluminum/silicon cylinder liners. The M278 has gasoline direct injection, piezoelectrically activated fuel injectors for more precise fuel delivery, and multi-spark ignition, which allows the spark plugs to be fired multiple times throughout the combustion sequence for more efficient combustion. In contrast to the port-injected M273, the M278 has these features. Other differences from the M273 include a wider range of adjustment for the variable valve timing system, a new timing chain configuration, and improved engine accessories (such the alternator, water pump, fuel pump, and oil pump) that lessen parasitic loads. The M276 V6 engine family, which was announced at, shares many of these new features.

Mercedes-Benz debuted their brand-new M278  engine in the fall of 2010 amid considerable excitement. The M272/3 engines were replaced by the M278 and its V6 sibling, the M278 Engine. It was initially offered in the 2011 Mercedes S550, 2011 Mercedes CL550, and 2011 Mercedes CLS550 vehicles.

The M278 is a 4.6L biturbo V8 engine with an initial output of 429 horsepower and 516 pound-feet of torque. By the end of its production cycle, some cars had their horsepower increased to 449. The M278 Engine consistently receives high marks from drivers for its dependability, engineering, and superior performance. Although it hasn’t been produced since the 2020 model year, it is still in high demand on the used market.

This manual will cover all the information we currently have on the Mercedes M278 engine, including its features, design, performance, and common issues. Let’s begin by examining the modifications Mercedes made to the engine from the M273, its forerunner.

What Cars Use the M278 engine Turbo?

The following Mercedes-Benz models used the M278:

2011-2017 S550 Mercedes-Benz
Mercedes-Benz CL550, 2011–2014
2015-2017 S550 Coupe by Mercedes-Benz
Mercedes-Benz SL550 2011-2018 and CLS550 2012-2020
2012-2014 E550 Mercedes-Benz
2012-2014 ML550 Mercedes-Benz
2013-2014 GL450 Mercedes-Benz
2013-2019 GL550/GLS550 Mercedes-Benz
The M157, an AMG-tuned high-performance variant of the M278 that was available in the following models:

2011-2017 S 63 AMG (W221/222)
2011-2014 CL 63 AMG
CLS 63 AMG, 2012–2018
2012-2015 ML 63 AMG
AMG GLE 63, 2015-2019

2012-2016 GL 63 AMG
2013-2018 G 63 AMG
2012-2016 E 63 AMG
2012-2019 SL 63 AMG
Additionally, the M152, a high-spec naturally aspirated variant of the M157, was used in the following model:

SLK 55 AMG, 2012–2016