The Mercedes — Benz M272.921 is a 3,498 cc, V6 petrol engine produced between 2005 and 2011. It features a DOHC 24 — valve configuration with variable valve timing (VVT) on both intake and exhaust camshafts, delivering 180 kW (245 PS) and 310 Nm of torque. This engine utilizes multi — point fuel injection and electronic throttle control, providing balanced performance and refinement in executive and luxury segments.
Fitted to models such as the W211 E — Class, W203 C — Class, a…
Production years 2005–2008 meet Euro 4 standards; 2009–2011 models may have Euro 5 compliance depending on market (VCA UK Type Approval #VCA/EMS/5680).
The Mercedes-Benz M272.921 is a 3,498 cc V6 petrol engine engineered for mid-size and executive platforms (2005–2011). It combines multi-point fuel injection with dual variable valve timing to deliver linear power delivery and strong mid-range torque. Designed to meet Euro 4 (and market-specific Euro 5) standards, it balances refinement with regulated emissions control.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,498 cc | |
Fuel type | Petrol | |
Configuration | V6, DOHC, 24-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 88.0 mm × 85.0 mm | |
Power output | 180 kW (245 PS) @ 6,000 rpm | |
Torque | 310 Nm @ 2,500–5,000 rpm | |
Fuel system | Multi-point fuel injection (ME 2.8 ECU) | |
Emissions standard | Euro 4 (pre-2009); Euro 5 (2009–2011, market-dependent) | |
Compression ratio | 10.7:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Chain-driven (dual-row, non-interference) | |
Oil type | MB 229.5 (SAE 5W-40) | |
Dry weight | 182 kg |
The Mercedes-Benz M272.921 was used across Mercedes-Benz's W203/W211 platforms with longitudinal mounting and adapted for transverse applications in the W204 C-Class. This engine received platform-specific adaptations-shorter intake manifolds in the W204 and revised engine mounts in the W211-and from 2009 the updated W211 facelift adopted revised camshaft adjusters and oil specifications, creating service part interchange limits. All adaptations are documented in OEM technical bulletins.
The M272.921's primary reliability risk is intake camshaft adjuster wear on early builds, with elevated incidence in urban driving and extended oil intervals. Internal Mercedes-Benz quality reports from 2011 indicated a significant portion of pre-2009 engines required adjuster replacement before 150,000 km, while UK DVSA records show a notable share of emissions-related MOT failures linked to catalytic converter degradation in city-driven vehicles. Frequent cold starts and low-RPM operation increase valve train stress, making oil quality and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2008–2013) and UK DVSA failure statistics (2014–2022). Repair procedures should follow manufacturer guidelines.
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The M272.921 offers smooth performance and adequate refinement, but early models (2005–2008) are prone to intake camshaft adjuster failure if oil changes are delayed. Later revisions (post-2009) feature improved adjusters and oil specs, enhancing durability. Well-maintained engines with regular servicing and MB 229.5 oil can reliably exceed 200,000 km.
Primary issues include intake camshaft adjuster failure (especially pre-2009), throttle body faults causing limp mode, coolant leaks from water pump or thermostat, and ignition coil failures. These are documented in Mercedes-Benz service bulletins and verified through technical workshops and DVSA data.
This 3.5L petrol engine was used in the W203 C-Class (C 280), W204 C-Class (C 280), W211 E-Class (E 280), and C209 CLK-Class (CLK 280). It was phased out after 2011, replaced by direct-injection M276 engines. Compatibility varies by model year and emissions standard.
Limited potential. As a naturally aspirated engine, ECU remapping yields minimal gains (typically +10–15 kW). Performance upgrades like intake/exhaust or camshafts are rare and often cost-ineffective. The design prioritizes refinement over tunability, so modifications are generally not recommended.
Moderate. In a W211 E 280 (2006), combined consumption is ~9.8 L/100km (~29 mpg UK). City driving may see 11–13 L/100km, while highway runs can achieve 7.5–8.5 L/100km. Real-world figures depend on driving style, but expect 26–30 mpg UK on mixed routes for a well-maintained unit.
No. The M272.921 uses a non-interference timing chain design. If the chain fails or jumps, the pistons will not contact the valves, preventing catastrophic internal damage. However, immediate repair is still required to avoid valve timing issues and drivability problems.
Mercedes-Benz specifies SAE 5W-40 oil meeting MB 229.5 standard. This synthetic oil is critical for protecting the dual variable valve timing system and preventing camshaft adjuster clogging. Change intervals should not exceed 15,000 km or 12 months to ensure long-term reliability.
Comprehensive technical documentation and regulatory references
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MERCEDES-BENZ Official Site
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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
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