Mercedes W205 engines

The Mercedes C-Class W205, which was launched in 2014, established itself as a technological pioneer in the premium mid-size segment and set new standards in terms of efficiency and performance. Over its production period until 2021, the model series underwent impressive engine development, ranging from economical four-cylinder engines to powerful V8 engines. The continuous further development of the drive technology reflects Mercedes' efforts to optimize both driving pleasure and environmental compatibility.

Mercedes W205 engines - market launch and BlueTEC technology (2014-2018)

The first generation of Mercedes W205 engines was characterized by a revolutionary downsizing strategy, in which Mercedes consistently relied on four-cylinder turbo engines for the first time. The reliability of most engines enables mileages of 250,000 to 350,000 kilometers with proper maintenance. Major repairs are typically due between 150,000 and 200,000 kilometers, mainly affecting turbochargers and injection systems. The OM651 2.1 BlueTEC with 170 hp is regarded as the absolute pinnacle of this generation and combines impressively smooth running with exceptional efficiency. The BlueTEC technology with AdBlue injection positioned Mercedes as a pioneer in clean diesel engines, while the new M274 petrol engines with direct injection and turbocharging put pressure on the competition from BMW and Audi.

Mercedes W205 BlueTEC diesel engines market launch (2014-2018)

The BlueTEC diesel engines of the W205 were based on the proven OM651 four-cylinder engine, which was refined with AdBlue technology and optimized turbocharging. The C 200 BlueTEC with 136 hp (engine code OM651.921), the C 220 BlueTEC with 170 hp (OM651.911) and the C 250 BlueTEC with 204 hp (OM651.901) were available. The 170 hp engine proved to be the optimum compromise between performance and consumption, while the 204 hp variant occasionally exhibited problems with exhaust gas recirculation from 120,000 kilometers. The weak points of all variants are the thermostat around 80,000 kilometers and occasional injector problems from 180,000 kilometers. The engines impress with their smooth running and low fuel consumption of 4.2 to 4.8 liters per 100 kilometers.

Mercedes W205 CGI petrol engines market launch (2014-2018)

The new M274 engine family revolutionized Mercedes' petrol engine range with advanced direct injection and turbocharging. The C 180 with 156 hp (M274.910), C 200 with 184 hp (M274.920) and C 250 with 211 hp (M274.920 in higher tuning) formed the core range. The 184 hp engine in particular impressed with its balanced characteristics and moderate susceptibility to problems. Typical weak points are the high-pressure pump from 100,000 kilometers and occasional problems with the piezo injectors from 150,000 kilometers. Consumption is between 6.2 and 7.1 liters, although the engines work very reliably with regular maintenance.

Mercedes W205 AMG engines market launch (2014-2018)

The AMG variants relied on proven V6 and V8 engines that were optimized for maximum performance. The C 43 AMG received the M276 V6 biturbo with 367 hp, while the C 63 AMG used the hand-assembled M177 V8 biturbo with 476 hp (C 63) or 510 hp (C 63 S). The V8 engine is considered to be exceptionally robust and can easily reach 200,000 kilometers as long as the engine oil is changed every 10,000 kilometers. Critical points are the turbocharger from 120,000 kilometers and occasional problems with the high-pressure fuel pump. Fuel consumption is between 9.2 and 11.8 liters, which is acceptable for this performance class.

Mercedes W205 engines - facelift and Euro 6d-TEMP (2018-2021)

The facelift of the Mercedes W205 engines brought with it a major overhaul of the powertrain range, focusing mainly on meeting stringent emissions standards. Reliability remained at a high level, with the revised engines typically reaching 280,000 to 400,000 kilometers. Maintenance intervals have been extended to 25,000 kilometers, while major repairs are usually only required after 180,000 kilometers. The revised OM654 diesel engine with 194 hp established itself as the benchmark for modern diesel technology and outperformed both BMW and Audi in terms of smoothness and efficiency. The EQ Boost technology with 48-volt mild hybrid system positioned Mercedes as a technology leader in the electrification of combustion engines.

Mercedes W205 OM654 diesel engine facelift (2018-2021)

The new OM654 four-cylinder diesel engine revolutionized Mercedes' diesel strategy with aluminium crankcase and optimized combustion management. Available as C 200 d with 160 hp (OM654.920), C 220 d with 194 hp (OM654.920 in higher tuning) and C 300 d with 245 hp (OM654.921 with additional turbocharger). The 194 hp engine is regarded as the absolute pinnacle of modern diesel technology and combines first-class running smoothness with fuel consumption of just 4.1 liters. Weak points are rare, occasionally problems with the AdBlue system occur after 150,000 kilometers. The engines are significantly quieter than their predecessors and offer impressive pulling power from low revs.

Mercedes W205 M264 petrol engines with EQ-Boost facelift (2018-2021)

The new M264 engine family integrated 48-volt mild hybrid technology into the C-Class for the first time and set new standards in efficiency and ride comfort. The C 200 EQ-Boost with 184 hp (M264.920) and C 300 EQ-Boost with 258 hp (M264.921) use an electric compressor for spontaneous throttle response. The EQ-Boost system reduces fuel consumption by up to 0.7 liters and completely eliminates turbo lag. The 48-volt battery can become problematic after 120,000 kilometers and occasionally the electric compressor after 100,000 kilometers. Fuel consumption is between 5.8 and 6.9 liters, which is exceptionally low for this performance class.

Mercedes W205 AMG engines facelift (2018-2021)

The revised AMG engines received particulate filters and optimized exhaust gas aftertreatment while maintaining the same performance. The C 43 AMG continued to use the M276 V6 biturbo with now 390 hp, while the C 63 AMG retained the M177 V8 biturbo with 476 hp (C 63) or 510 hp (C 63 S). In addition, the extreme C 63 S Black Series with 730 hp was added, although this was only produced in limited numbers. The engines are very reliable, with the V8 easily reaching 250,000 kilometers with proper maintenance. Critical components are the turbochargers from 140,000 kilometers and the high-pressure pumps, which should be checked every 150,000 kilometers.

Conclusion: The best Mercedes W205 engines of all generations

The engine development of the Mercedes W205 reflects the successful transition from traditional naturally aspirated engines to highly efficient turbocharged engines with hybrid support. Across all generations, the Mercedes W205 engines have proven to be reliable and technically advanced drives that optimally combine both driving pleasure and economy.

• Best Mercedes W205 gasoline engine:

The M264 2.0 EQ-Boost with 184 hp from the facelift impresses with the perfect combination of mild hybrid technology, low fuel consumption and excellent reliability.

• Best Mercedes W205 diesel engine:

The OM654 2.0 with 194 hp is considered the reference of modern diesel technology and offers exceptionally smooth running with minimal fuel consumption of just 4.1 liters.

• Sportiest Mercedes W205 engine:

The hand-assembled M177 4.0 V8 biturbo with 476 hp in the C 63 AMG combines brutal performance with surprising everyday suitability and achieves high mileages with proper maintenance.

At AUTODOC you will find high-quality spare parts for all Mercedes W205 engines at reasonable prices.