The Mercedes — Benz M 273.965 is a 5,461 cc, 90° V8 petrol engine produced between 2005 and 2011. It features double overhead camshafts (DOHC), variable valve timing (VVT) on both intake and exhaust camshafts, and naturally aspirated operation with multi — point fuel injection. In standard tuning, it delivered 225 kW (306 PS) and 460 Nm of torque, providing smooth high — speed performance and linear power delivery.
Fitted to flagship models including the W221 S — Class, W211…
All production years 2005–2011 meet Euro 4 emissions standards .
The Mercedes-Benz M 273.965 is a 5,461 cc 90° V8 engineered for full-size luxury and performance models (2005–2011). It combines naturally aspirated design with dual variable valve timing to deliver smooth, linear power and high-speed refinement. Designed to meet Euro 4 standards, it balances performance with drivability in premium applications.
| Parameter | Value | Source |
|---|---|---|
Displacement | 5,461 cc | |
Fuel type | Petrol | |
Configuration | 90° V8, DOHC, 32-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 98.0 mm × 90.5 mm | |
Power output | 225 kW (306 PS) @ 6,000 rpm | |
Torque | 460 Nm @ 2,700–4,000 rpm | |
Fuel system | Sequential multi-point fuel injection (ME 2.8 control unit) | |
Emissions standard | Euro 4 | |
Compression ratio | 10.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | N/A | |
Timing system | Dual chain (short-block to cylinder heads) | |
Oil type | Refer to vehicle handbook / manufacturer specification | |
Dry weight | 210 kg |
The Mercedes-Benz M 273.965 was used across Mercedes-Benz's W211, W221, and W164 platforms with longitudinal mounting. This engine received platform-specific calibrations-adaptive throttle response in the S-Class and revised torque delivery in the ML-Class-and from 2008, minor internal revisions improved cam adjuster durability, creating service part interchange limits. All adaptations are documented in OEM technical bulletins.
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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.
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The M 273.965 is a robust V8 with strong build quality, but pre-2008 models are prone to camshaft adjuster wear if oil changes are delayed. Later revisions improved durability, so well-maintained engines can exceed 200,000 km. Using MB 229.5 oil and adhering to 15,000 km service intervals is essential for longevity.
The primary issues are intake camshaft adjuster wear (causing rattles and timing faults), oil leaks from ageing valve cover gaskets, and ignition coil failures leading to misfires. Throttle body actuator faults and spark plug degradation are also frequent. These are documented in Mercedes service bulletins and technical forums.
This 5.5L V8 was used in several flagship models: S-Class (W221) S 350 (2005–2011), E-Class (W211) E 350 (2005–2009), ML-Class (W164) ML 350 (2006–2011), and R-Class (W251) R 350 (2006–2010). All models meet Euro 4 emissions standards.
Yes, though it's naturally aspirated. ECU remapping can yield +15–25 kW by optimizing throttle response and ignition timing. Performance gains are modest compared to turbo engines. Supporting mods like exhaust and intake upgrades improve results. Tuning should not compromise cam adjuster oil pressure requirements.
Moderate for a V8. In an S 350 (W221), combined consumption is ~10.5 L/100km (~27 mpg UK). City driving may reach 13–15 L/100km (~19–15 mpg), while highway cruising can achieve ~8.5 L/100km (~33 mpg). Real-world figures depend on driving style, but expect 18–25 mpg (UK) in mixed conditions.
Yes. The M 273 series is an interference engine. If the timing chain fails or jumps, pistons can contact open valves, resulting in severe internal damage. Chain maintenance is critical—any unusual noise from the front of the engine should prompt immediate inspection.
Mercedes specifies SAE 5W-40 oil meeting MB 229.5 standard. This low-ash, high-detergent formulation protects the cam adjusters and maintains engine cleanliness. Oil must be changed every 15,000 km or annually to prevent sludge and wear in critical hydraulic components.
Comprehensive technical documentation and regulatory references
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Regulatory Stability
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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
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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