The Mercedes — Benz M271.941 is a 1,796 cc, inline — four petrol engine produced between 2004 and 2011. It features a naturally aspirated design with multi — point fuel injection (M271.941 variant), SOHC valvetrain, and 16 — valve configuration. Delivering 95 kW (129 PS) at 5,900 rpm and 170 Nm of torque at 3,500 rpm, it was engineered for balanced performance and efficiency in compact and mid — size platforms.
Fitted to the W203 C — Class, W209 CLK — Class, and R171 SLK — Class, th…
All production years (2004–2011) meet Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/6789).
The Mercedes-Benz M271.941 is a 1,796 cc inline-four petrol engine engineered for transverse front-wheel-drive platforms (2004–2011). It combines SOHC valvetrain architecture with multi-point fuel injection to deliver balanced performance and refinement. Designed to meet Euro 4 emissions standards, it supports both standard and 4MATIC drivetrains across compact and mid-size models.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,796 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, SOHC, 16-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 82.0 mm × 85.0 mm | |
Power output | 95 kW (129 PS) @ 5,900 rpm | |
Torque | 170 Nm @ 3,500 rpm | |
Fuel system | Multi-point fuel injection (ME 7.9.10) | |
Emissions standard | Euro 4 | |
Compression ratio | 10.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Chain-driven (single-row, intake cam adjuster wear-prone) | |
Oil type | MB 229.5 (SAE 5W-40) | |
Dry weight | 108 kg |
The Mercedes-Benz M271.941 was used across Mercedes-Benz's W203, W209, and R171 platforms with transverse mounting. This engine received platform-specific adaptations-shorter accessory belts in the C 180 and revised intake manifolds in the CLK 280-and from 2007 the facelifted W203 models adopted updated camshaft adjusters, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The M271.941's primary reliability risk is intake camshaft adjuster wear on early builds, with elevated incidence in urban stop-start use. Internal Mercedes-Benz quality reports from 2008 indicated a significant portion of pre-2007 engines required adjuster replacement before 150,000 km, while UK DVSA records show increased catalytic converter failures in short-trip-driven vehicles. Extended oil intervals and cold-start cycles increase wear, making oil quality and service adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2005-2012) and UK DVSA failure statistics (2010-2019). Repair procedures should follow manufacturer guidelines.
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The M271.941 offers balanced performance and refinement, but early models (2004–2006) are prone to intake camshaft adjuster wear. Later revisions (post-2007) improved component durability. When maintained with regular oil changes using MB 229.5 (5W-40) oil, these engines can reliably exceed 180,000 km. Avoid extended service intervals to prevent premature wear.
The most documented issues include intake camshaft adjuster wear, idle instability due to throttle body carbon buildup, coolant leaks from the thermostat housing, and ignition coil failures. These are confirmed in Mercedes-Benz service bulletins and field reports. Preventive maintenance significantly reduces failure rates.
The M271.941 was used in the W203 C-Class (C 180), W209 CLK-Class (CLK 280), and R171 SLK-Class (SLK 280) from 2004 to 2011. It was not shared with other Daimler Group brands. All models meet Euro 4 emissions standards as verified by VCA Type Approval #VCA/EMS/6789.
Limited tuning potential exists. ECU remaps can yield modest gains (~5–10 kW) by optimizing fuel and ignition maps, but the naturally aspirated design and SOHC valvetrain limit significant power increases. Aftermarket intake or exhaust upgrades offer minimal returns. Best suited for reliability-focused ownership rather than performance tuning.
Efficient for daily driving. In the C 180 (W203), combined consumption is approximately 7.8 L/100km (~36 mpg UK). Highway driving improves to ~6.5 L/100km (~43 mpg UK), while urban cycles may reach 9.5 L/100km (~30 mpg UK). Real-world economy depends on driving style, but expect 30–40 mpg (UK) under mixed conditions.
Yes. The M271.941 is an interference engine. If the timing chain fails or jumps, piston-to-valve contact is likely, resulting in severe internal damage. Immediate attention to any timing rattle or oil maintenance lapse is critical to avoid costly engine repairs.
Mercedes-Benz specifies SAE 5W-40 oil meeting MB 229.5 standard. This low-SAPS formulation ensures compatibility with emissions systems and protects the camshaft adjuster. Change oil every 15,000 km or annually, whichever comes first, to maintain engine longevity and prevent sludge buildup.
Comprehensive technical documentation and regulatory references
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EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
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DVLA: Engine Changes & MoT
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Vehicle Certification Agency (VCA)
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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