The Mercedes — Benz M271.957 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 responsive performance and improved fuel efficiency. In standard tune it produced 115 kW (156 PS), with higher — output versions reaching 135 kW (184 PS) and torque outputs between 230–270 Nm, making it ideal for compact and mid — size platforms.
Fitted to models su…
All production years (2008–2015) meet Euro 5 emissions standards (VCA UK Type Approval #VCA/EMS/5679).
The Mercedes-Benz M271.957 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 Mercedes-Benz M271.957 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.
The M271.957'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.
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The M271.957 offers strong performance and efficiency, but early models (2008-2011) had HPFP reliability concerns. Later revisions (post-2012) improved pump durability, so well-maintained examples can exceed 180,000 km. Regular servicing with MB 229.51 oil and adherence to 15,000 km intervals greatly enhance longevity.
Key issues include high-pressure fuel pump failure, intake valve carbon buildup, turbo actuator faults, and electric coolant pump failures. These are documented in Mercedes-Benz service bulletins, particularly SIB 203070/13 for HPFP concerns. Carbon cleaning and timely oil changes are essential preventative measures.
This 1.8L turbo petrol was used in the A-Class (W169), B-Class (W245), and C-Class SportCoupe (CL203) from 2008-2015. It powered variants including A180, A200, A250, B180, B200, C200, and C250. Chrysler also used CGI injection technology derived from this engine in the 300C (2011-2014).
Yes. The M271 is highly tunable via ECU remap. Stage 1 tunes typically add +30-50 kW safely, as stock internals handle increased torque. Aftermarket upgrades (intercooler, exhaust) allow further gains. Tuning requires premium fuel (RON 98) and robust cooling to avoid knock or turbo damage.
In an A250 (135 kW) from 2013, combined consumption is ~7.5 L/100 km (~38 mpg UK). Highway driving can achieve ~6.2 L/100 km (~45 mpg UK). Real-world figures vary, but expect 35-45 mpg UK on mixed roads. Performance variants (A250) consume more under spirited driving.
No. The M271.957 uses a non-interference valvetrain design. If the timing chain fails, piston-to-valve contact is unlikely, reducing risk of catastrophic engine damage. However, timing chain replacement is still recommended per service schedule to prevent drivability issues.
Mercedes specifies MB 229.51 (5W-30) synthetic oil. This low-SAPS formulation is essential for turbo and direct injection system protection. Change oil every 15,000 km or annually to prevent HPFP wear and carbon buildup.
Comprehensive technical documentation and regulatory references
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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