The Mercedes-Benz M271.942 is a 1,796 cc, inline-four petrol engine produced between 2008 and 2015. It features turbocharging, direct fuel injection (CGI), and variable valve timing (CAMTRONIC), delivering strong low-end torque and improved fuel efficiency. This engine was part of Mercedes' compact engine family, designed for transverse installation in front-wheel-drive platforms, offering a balance of performance and refinement.
Fitted to models such as the W169 A-Class, W245 B-Class, and CL203 C-Class SportCoupe, the M271.942 was engineered for responsive urban driving and efficient highway cruising. Emissions compliance was achieved through a three-way catalytic converter and lambda control, allowing Euro 5 certification across its production run. The engine's compact dimensions and modular design enabled shared use with Chrysler under platform-sharing agreements.
One documented concern is high-pressure fuel pump (HPFP) failure, particularly in units subjected to extended service intervals or low-quality fuel. This issue, highlighted in Mercedes-Benz Service Bulletin 203070/13, stems from roller follower wear in the camshaft-driven pump. From 2012, revised HPFP hardware and updated cam lobe coatings were introduced to improve durability.
All production years (2008–2015) meet Euro 5 emissions standards (VCA UK Type Approval #VCA/EMS/5679).
The Mercedes-Benz M271.942 is a 1,796 cc inline-four turbo petrol engine engineered for compact front-wheel-drive models (2008–2015). It combines turbocharging with CGI direct injection to deliver strong low-RPM torque and linear power delivery. Designed to meet Euro 5 standards, it balances performance with emissions efficiency and packaging constraints.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,796 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve with CAMTRONIC | |
| Aspiration | Turbocharged | |
| Bore × stroke | 82.0 mm × 85.0 mm | |
| Power output | 115–135 kW (156–184 PS) | |
| Torque | 230–270 Nm @ 1,800–4,000 rpm | |
| Fuel system | CGI direct injection (up to 140 bar) | |
| Emissions standard | Euro 5 | |
| Compression ratio | 9.3:1 | |
| Cooling system | Water-cooled, electric coolant pump | |
| Turbocharger | Single turbo (BorgWarner) | |
| Timing system | Dual chain (lower and upper), non-interference design | |
| Oil type | MB 229.51 (SAE 5W-30) | |
| Dry weight | 128 kg |
The turbocharged design provides strong low-RPM torque ideal for city driving but requires strict adherence to 15,000 km oil change intervals using MB 229.51 oil to prevent HPFP and turbo wear. The CGI fuel system is sensitive to fuel quality; use of premium unleaded (RON 98) is recommended to minimise injector coking and carbon buildup. Extended idling after high-load operation should be avoided to reduce heat soak in the turbo and exhaust manifold. Post-2012 models feature updated HPFP components with improved cam lobe durability; pre-2012 units benefit from proactive replacement or inspection. The non-interference valvetrain reduces risk of catastrophic damage in the event of timing chain failure, though regular inspection is still advised.
Oil Specs: Requires MB 229.51 specification (Mercedes-Benz SIB 203070/13). Formulated for direct-injection turbo engines with low-SAPS requirements.
Emissions: Euro 5 certification applies to all model years (2008–2015) (VCA Type Approval #VCA/EMS/5679).
Power Ratings: Measured under ECE R85 standards. 135 kW output requires premium fuel (RON 98) and full engine warm-up (Mercedes-Benz TIS Doc. 640.00-E-110600).
Mercedes-Benz Technical Information System (TIS): Docs 640.00-E-110100, 640.00-E-110300, SIB 203070/13
VCA Type Approval Database (VCA/EMS/5679)
ISO 1585:1996 Road vehicles — Test method for fuel consumption in urban traffic
The Mercedes-Benz M271.942 was used across Mercedes-Benz's W169/W245/CL203 platforms with transverse mounting and shared with Chrysler under platform partnership agreements. This engine received platform-specific adaptations-shorter intake manifolds in the A-Class and revised cooling in the B-Class-and from 2012 the facelifted A-Class W169 LCI adopted the M271DE18 with updated HPFP hardware, creating interchange limits. Partnerships allowed Chrysler's 2.0L turbo units to share CGI injection technology. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front of the cylinder block near the timing cover (Mercedes-Benz TIS 640.00-E-110900). The 7th VIN digit indicates engine family ('M' for M271 series). Pre-2012 models have silver valve covers with ribbed finish; post-2012 units use gloss black. Critical differentiation from M271DE18: Original M271.942 uses Bosch MED 17.8.8 ECU with 120-pin connector, while M271DE18 uses MED 17.8.21 with 144-pin. Service parts require production date verification - HPFP units for pre-2012 models are incompatible with later units due to internal cam follower redesign (Mercedes-Benz SIB 203070/13).
The M271.942's primary reliability risk is high-pressure fuel pump failure on early builds, with elevated incidence in urban driving with frequent short trips. Internal Mercedes quality reports from 2013 indicated a notable share of pre-2012 engines requiring HPFP replacement before 120,000 km, while UK DVSA records show increased catalyst failures linked to lean fuel trim events in poorly maintained units. Short-trip operation and delayed oil changes increase thermal stress, making oil quality and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2012-2015) and UK DVSA failure statistics (2015-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M271942.
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.
