The Mercedes — Benz M271.951 is a 1,796 cc, inline — four petrol engine produced between 2008 and 2015. It features a dual overhead camshaft (DOHC) valvetrain with variable valve timing (VVT) on both intake and exhaust camshafts and multi — point fuel injection (MPFI). In tuned form, it delivers 135 kW (184 PS) and 270 Nm of torque, offering enhanced responsiveness for compact executive applications.
Fitted to models such as the W204 C — Class, W212 E — Class, and R172 SLK, the M…
Production years 2008–2015 meet Euro 5 emissions standards .
The Mercedes-Benz M271.951 is a 1,796 cc inline-four petrol engine engineered for compact and mid-size platforms (2008–2015). It combines multi-point fuel injection with dual variable valve timing to deliver responsive performance and improved fuel efficiency. Designed to meet Euro 5 standards, it balances sporty driving dynamics with everyday usability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 1,796 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 82.0 mm × 85.0 mm | |
Power output | 135 kW (184 PS) @ 5,500 rpm | |
Torque | 270 Nm @ 2,800–4,600 rpm | |
Fuel system | Multi-point fuel injection (MPFI) | |
Emissions standard | Euro 5 | |
Compression ratio | 10.7:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Timing chain (double-row, front-mounted) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 148 kg |
The Mercedes-Benz M271.951 was used across Mercedes-Benz's W204/W212/R172 platforms with longitudinal mounting and no licensed partnerships. This engine received platform-specific adaptations-shortened intake manifolds in the R172 and revised cooling routing in the W212-and from 2011 the updated camshaft adjuster design was implemented across all applications, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Engine Finders UK Ltd, which operates EngineCode.uk, can pass your enquiry to engine suppliers in the UK. The service is for vehicles in the United Kingdom, with UK delivery or fitting. This is a commercially connected service, and sending an enquiry does not confirm diagnosis or compatibility.
Diagnostic reminder: If a technician has recommended replacing the engine, you can send an enquiry to engine suppliers in the UK. Confirm the diagnosis first: an engine-code record does not diagnose a fault.
Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.
Analysis derived from manufacturer technical service bulletins and industry workshop records. Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The M271.951 offers responsive performance and good refinement, but early models (2008-2010) had reliability concerns, particularly dual camshaft adjuster failures. Later revisions (post-2011) improved adjuster durability, so well-maintained examples can be quite robust. Regular servicing and using high-quality oil (5W-40 MB 229.5) greatly aid longevity.
The biggest issues are dual camshaft adjuster wear (leading to startup rattle or VVT faults), intake carbon buildup affecting throttle response, and lambda sensor degradation causing poor fuel economy. Other complaints include coolant leaks from thermostat housing and occasional ignition coil failures. These are well-documented in Daimler service bulletins.
This 1.8L petrol engine was used across several Mercedes-Benz platforms. It appeared in the C-Class (W204), E-Class (W212), and SLK (R172) as the C 200 Kompressor, E 200 Kompressor, and SLK 200 Kompressor. Smart also used a transverse-adapted version in the Fortwo (W454) from 2011-2015.
Aftermarket ECU tuning is common on the M271951 platform, but increasing boost or altering engine parameters accelerates component wear, impacts emissions compliance, and may void vehicle warranties. Any modifications should be evaluated carefully by a qualified specialist.
Moderate. In a C 250 (W204) from around 2010, typical consumption is ~9.8 L/100km (city) and ~6.5 L/100km (highway), or about 29 mpg UK combined. Real-world figures depend on driving style, but expect 28-33 mpg (UK) on mixed roads for a healthy M271.951. Premium fuel (RON 98) is recommended for optimal efficiency.
Yes. The M271 series is an interference engine. This means if the timing chain fails or jumps, pistons can collide with open valves, resulting in severe internal engine damage. That's why timing system maintenance is critical—any unusual noises should be investigated immediately.
Mercedes-Benz specifies a 5W-40 synthetic oil meeting MB 229.5 specification. Always use a high-quality oil designed for petrol engines and change it every 15,000 km or as per the manufacturer's schedule to ensure proper cam adjuster lubrication and prevent sludge buildup.
Comprehensive technical documentation and regulatory references
EngineCode.uk is operated by Engine Finders UK Ltd. It provides engine-reference information and an optional commercial enquiry service. It is not an official manufacturer website. Check the record's sources and confirm vehicle-specific details before relying on it for parts, repairs or replacement.
Our editorial standard prioritises relevant manufacturer documentation and official regulatory sources. The sources and verification status for a record should be checked alongside the data.
A statement is not verified merely because a source is listed. Where supporting evidence is missing or conflicting, the record should identify that limitation. Please report unsupported or inconsistent information.
Transparency in gaps
A missing or unverified value does not mean the manufacturer has withheld it. We distinguish information not yet verified, information not available to us, and information explicitly not disclosed by the source.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Records are subject to review and correction. Source links, dates and verification notes should be read with the technical information. Our Editorial and Sourcing Policy explains our standards and review process.
Found an error or missing source? Report a problem with this page. Include the field or statement concerned and a supporting source if available. You can also email corrections@enginecode.uk.
Copyright and permissions
Images and other material may be protected by copyright. Attribution does not by itself grant permission to reuse material. If you believe material on this site infringes your rights, contact copyrights@enginecode.uk with the page URL and details of your claim. We will review the material and take appropriate action.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
Our Privacy Policy explains how Engine Finders UK Ltd uses information from visits, vehicle lookups, enquiries and messages. Our Cookie Policy explains cookies and similar technologies and how to change your choices.
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
Ownership and commercial services
EngineCode.uk is owned and operated by Engine Finders UK Ltd. Alongside our reference content, we offer an optional replacement-engine enquiry service through Engine Finders and may identify relevant services provided by businesses connected with us. These commercial connections are disclosed. Using an enquiry service is not required to read our reference content.
Engine Finders UK Ltd operates this website. Our optional enquiry service has a commercial purpose. Our Ownership and Commercial Disclosure explains the relationship between the reference website and that service. Participating suppliers pay a fee or subscription to participate on the network and receive quote requests.
Use this record as a starting point for identification. Specifications and vehicle applications may contain errors or omissions. Confirm the exact engine variant and compatibility using vehicle-specific documentation and a qualified supplier or technician.
All external links open in new tabs. Please verify current availability of resources.