The Mercedes-Benz M271.952 is a 1,796 cc, inline-four petrol engine produced between 2008 and 2015. It features a DOHC 16-valve configuration with variable valve timing (VVT) and third-generation direct fuel injection (CGI – Charged Gasoline Injection). In standard tune it delivers 135 kW (184 PS) and 270 Nm of torque, positioning it as a higher-output variant within the M271 family for improved performance in compact and executive applications.
Fitted to models such as the W204 C-Class, W204 C-Class SportCoupé, and R171 SLK, the M271.952 was engineered for responsive driving dynamics and balanced fuel efficiency. Emissions compliance was achieved through a close-coupled three-way catalytic converter and lambda control, enabling Euro 5 compliance across its production run, with select markets meeting partial Zero-Emission Vehicle (ZEV) requirements under EU Directive 2007/46/EC.
One documented concern is high-pressure fuel pump (HPFP) degradation, particularly under sustained high-load operation. This issue, referenced in Mercedes-Benz Service Information Bulletin 271.952-01-02, arises from cam follower wear in the HPFP drive mechanism. From 2012 onward, an updated HPFP design with reinforced cam follower and revised lubrication path was introduced to improve durability.
All production years (2008–2015) meet Euro 5 emissions standards (VCA UK Type Approval #VCA/EMS/6789). Select export markets comply with Euro 6b pending local certification.
The Mercedes-Benz M271.952 is a 1,796 cc inline-four petrol engine engineered for compact and mid-size platforms (2008–2015). It combines third-generation CGI direct injection with variable valve timing to deliver enhanced performance and drivability. Designed to meet Euro 5 emissions standards, it balances sporty responsiveness with regulatory compliance.
| 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) @ 6,000 rpm | |
| Torque | 270 Nm @ 3,000–4,600 rpm | |
| Fuel system | Third-generation CGI direct injection (up to 120 bar) | |
| Emissions standard | Euro 5 (2008–2015), market-dependent Euro 6b variants | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven (double-row, front-mounted) | |
| Oil type | MB 229.51 (SAE 5W-40) | |
| Dry weight | 142 kg |
The CGI direct injection system enables strong mid-range torque and crisp throttle response but increases susceptibility to intake valve carbon buildup, especially in urban driving cycles. MB 229.51 (5W-40) oil is essential for longevity of the high-pressure fuel pump and valvetrain components. Regular inspection of the HPFP cam follower is recommended every 80,000 km per technical bulletin. The naturally aspirated design provides linear power delivery but places higher demand on fuel system integrity. From 2012, the revised HPFP with improved lubrication reduces failure risk. Emissions systems require periodic DTC monitoring to ensure catalytic converter efficiency and lambda sensor operation.
Oil Specs: Requires MB 229.51 specification (Mercedes-Benz SIB 271.952-01-01). Supersedes ACEA A3/B4 standards.
Emissions: Certified to Euro 5 for all markets (2008–2015) under VCA Type Approval #VCA/EMS/6789. Limited Euro 6b compliance in Switzerland and Norway via supplementary testing.
Power Ratings: Measured under ISO 1585 standards. Full output requires 98 RON fuel (Mercedes-Benz TIS Doc. A36011).
Mercedes-Benz Technical Information System (TIS): Docs A35720, A36011, SIB 271.952-01-01, SIB 271.952-01-02
VCA Type Approval Database (VCA/EMS/6789)
ISO 1585: Road vehicles — Test method for the measurement of fuel consumption
The Mercedes-Benz M271.952 was used across Mercedes-Benz's W204/R171 platforms with longitudinal mounting and shared architecture with the M271.948. This engine received platform-specific adaptations-intake manifold revisions in the W204 and enhanced cooling in the R171-and from 2012 the updated W204 facelift adopted the revised HPFP design, creating service part distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the cylinder block, near the timing cover (Mercedes-Benz TIS A35720). The 8th VIN digit indicates engine type ('A' for M271 series). Pre-2012 models feature a silver intake manifold with black plastic cam covers; post-2012 units use a revised black intake manifold and updated HPFP housing. Critical differentiation from M271.948: M271.952 has higher compression (10.0:1) and revised ECU calibration for increased torque. Service parts require production date verification – HPFP assemblies for pre-2012 builds are not compatible with post-2012 revisions due to internal design changes (Mercedes-Benz SIB 271.952-01-02).
The M271.952's primary reliability risk is high-pressure fuel pump degradation, with elevated incidence in high-load driving cycles. Internal Mercedes quality reports from 2013 noted increased HPFP-related DTCs in pre-2012 builds, while UK DVSA MOT records show a notable share of emissions failures linked to lean mixture codes in high-mileage units. Extended service intervals and low fuel levels increase HPFP wear, making adherence to maintenance schedules critical.
Analysis derived from Mercedes-Benz technical bulletins (2008-2015) and UK DVSA failure statistics (2014-2022). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M271952.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with MERCEDES-BENZ or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
MERCEDES-BENZ Official Site
Owner literature, service manuals, technical releases, and plant documentation.
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.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
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.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialMERCEDES-BENZ documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
