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10 September 2025 Mercedes S205 engines
The Mercedes C-Class S205 was launched in 2014 as a Estate and quickly established itself as a premium alternative to the Audi A4 Avant and BMW 3 Series Touring. Over its production period until 2021, the S205 range offered an impressive variety of engines from economical diesels to high-performance AMG engines, reflecting Mercedes' technological development in the mid-size class.
Mercedes S205 engines (2014-2021)
The Mercedes S205 represented a new era of the C-Class with significantly improved material quality and state-of-the-art engine technology. Reliability varied greatly depending on the engine type: while the tried-and-tested Mercedes S205 engines such as the 2.2-liter diesel easily reached 400,000 to 500,000 kilometers with proper maintenance, the early M274 petrol engines often required costly repairs to the timing chain or balancer shafts between 150,000 and 200,000 kilometers. The absolute top engine of this generation was the C 220 d with 170 hp, which optimally combined power, reliability and economy. Technical highlights included the 9G-TRONIC transmission from 2016 and the introduction of the M264 engine with mild hybrid technology from 2018. In the premium segment, the S205 successfully positioned itself between the sportier BMW 3 Series and the comfort-oriented Audi A4 family.
Mercedes S205 petrol engines (2014-2021)
The Mercedes S205 petrol engine range started with the M274 engine in various power levels. The C 180 had a 1.6-liter turbo with 156 hp, while the C 200 offered a 2.0-liter turbo with 184 hp. From 2016, the C 250 with 211 hp was added. These early Mercedes S205 engines suffered from typical M274 problems: Timing chain rattling, defective balancer shafts and occasional turbocharger damage made them the most problematic engines in the series. The M274 engine in the C 250 proved to be particularly susceptible to engine damage caused by chain jumps. From 2018, the much more reliable M264 engine was introduced, initially in the C 200 with 184 hp and later in the C 300 with 258 hp. The M264 featured integrated starter-generator technology (ISG) and 48-volt on-board system, making it the most advanced Mercedes S205 petrol engine.
Mercedes S205 diesel engines (2014-2021)
The Mercedes S205 diesels were dominated by the tried-and-tested OM651 engine in various configuration levels. The C 220 d started with 170 hp, later a 194 hp version was added. The smaller C 200 d offered 136 hp, while the powerful C 250 d topped the range with 204 hp. These Mercedes S205 TDI engines proved to be exceptionally reliable and economical - the C 220 d with 170 hp in particular became the bestseller and most reliable engine in the entire series. All diesels had modern common-rail injection with up to 2000 bar pressure, SCR catalytic converter and particulate filter as standard. The OM651 already met the Euro 6 standard and offered test fuel consumption of just 4.2 to 5.8 liters per 100 km. The only weak point was occasionally the AdBlue dosing unit, which could fail after around 200,000 km.
Mercedes S205 AMG engines (2014-2021)
The high-performance variants of the Mercedes S205 were powered by AMG engines. The C 43 AMG received a 3.0-liter V6 biturbo (M276) with 367 hp from 2016, later increased to 390 hp. The C 63 AMG relied on the legendary 4.0-liter V8 biturbo (M177) with 476 hp in the standard version and 510 hp in the S version. These Mercedes S205 engines offered impressive performance, but were high-maintenance and occasionally had problems with the turbochargers under extreme load. The M177 engine was considered one of the best V8 engines of its generation, but required more frequent oil changes and high-quality fluids.
| Mercedes S205 engine | Power output | Fuel consumption | Typical weaknesses | Rating |
|---|---|---|---|---|
| C 180 (M274) | 156 HP | 6.4-7.2 l/100km | Timing chain, balancer shafts | Problematic |
| C 200 (M274) | 184 HP | 6.8-7.6 l/100km | Timing chain, turbocharger | Moderate |
| C 250 (M274) | 211 HP | 7.2-8.1 l/100km | Chain jump, engine damage | Problematic |
| C 200 (M264) | 184 HP | 6.2-7.0 l/100km | Very reliable | Very good |
| C 300 (M264) | 258 HP | 6.8-7.4 l/100km | Mild hybrid, robust | Good |
| C 200 d | 136 HP | 4.2-4.8 l/100km | AdBlue dosing | Good |
| C 220 d | 170-194 HP | 4.4-5.2 l/100km | Very robust | Very good |
| C 250 d | 204 HP | 4.8-5.8 l/100km | AdBlue system | Good |
| C 43 AMG | 367-390 HP | 8.6-9.4 l/100km | Turbocharger under extreme load | Good |
| C 63 AMG | 476-510 HP | 10.2-11.8 l/100km | Maintenance-intensive, turbocharger | Average |
Conclusion: The best Mercedes S205 engines of all generations
The development of the Mercedes S205 engines clearly shows Mercedes' transition from problematic early turbo engines to mature mild hybrid technology. While the diesel engines consistently impressed with their high reliability, the early M274 petrol engines struggled with considerable quality problems, which were only resolved with the M264 engine.
- Best Mercedes S205 gasoline engine:
The C 200 with M264 engine (184 hp, from 2018) combines modern mild hybrid technology with high efficiency and excellent reliability.
- Best Mercedes S205 diesel engine:
The C 220 d with OM651 engine (170 hp) offers the best combination of reliability, economy and suitability for everyday use over the entire production period.
- Best Mercedes S205 performance engine:
The C 43 AMG with M276 V6 biturbo (390 hp) combines sporty performance with still acceptable everyday practicality and reliability.
For maintenance and spare parts for all Mercedes S205 variants, AUTODOC offers a comprehensive range of original and quality spare parts with fast delivery and expert advice.
