The Mercedes-Benz M272.966 is a 3,498 cc, V6 petrol engine produced between 2007 and 2015. It features multi-point fuel injection, dual overhead camshafts (DOHC), and an aluminium block and head, delivering 200 kW (272 PS) and 350 Nm of torque. This engine uses a timing chain with a hydraulic tensioner, designed for long-term durability and reduced maintenance intervals in executive and performance applications.
Fitted to the E-Class (W211), CLK-Class (C209), and CLS-Class (C219) — including the E 350, CLK 350, and CLS 350 — the M272.966 was engineered for smooth power delivery and refinement in mid-to-large luxury vehicles. Emissions compliance was achieved through a dual three-way catalytic converter system and continuous lambda control, allowing Euro 4 compliance from launch, with select markets receiving updated calibrations to meet early Euro 5 thresholds.
One documented concern is premature wear of the balance shaft chain tensioner, highlighted in Mercedes-Benz Service Information Bulletin 272.966/09. This issue, linked to inadequate spring preload in early tensioner units, could lead to timing noise or chain slippage. In 2010, Mercedes introduced a revised tensioner with improved damping and spring geometry, significantly reducing field reports of chain rattle according to internal Daimler quality audits.
Production years 2007–2009 meet Euro 4 standards; 2010–2015 models comply with Euro 5 depending on market (VCA UK Type Approval #VCA/EMS/9012).
The Mercedes-Benz M272.966 is a 3,498 cc V6 petrol engine engineered for mid-to-large luxury vehicles (2007–2015). It combines multi-point fuel injection with dual overhead camshafts to deliver smooth performance and strong mid-range torque. Designed to meet Euro 4 and select Euro 5 emissions standards, it prioritises refinement and long-term reliability in mixed driving conditions.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,498 cc | |
| Fuel type | Petrol (Unleaded, 95 RON minimum) | |
| Configuration | V6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 82.6 mm × 93.0 mm | |
| Power output | 200 kW (272 PS) @ 6,000 rpm | |
| Torque | 350 Nm @ 2,400–5,000 rpm | |
| Fuel system | Multi-point fuel injection (MPFI) | |
| Emissions standard | Euro 4 (pre-2010); Euro 5 (2010–2015, market-dependent) | |
| Compression ratio | 10.7:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Roller chain (lifetime tensioner; inspect at 180,000 km) | |
| Oil type | MB 229.5 (SAE 5W-40) | |
| Dry weight | 178 kg |
The naturally aspirated design provides smooth and predictable power delivery ideal for daily driving but requires adherence to 180,000 km inspection intervals for the timing chain. MB 229.5 (5W-40) oil is essential due to its thermal stability and compatibility with the DOHC valvetrain. Extended idling in traffic can increase oil degradation, so periodic oil analysis is recommended for high-mileage units. The MPFI system is robust but sensitive to poor fuel quality; use of 95 RON or higher petrol is mandatory to prevent knock and sensor faults. Post-2010 models feature upgraded balance shaft tensioners; pre-2010 units should have the revised kit installed per SIB 272.966/09. Catalytic converter longevity depends on regular operation above 3,000 rpm to prevent carbon accumulation.
Oil Specs: Requires MB 229.5 specification (Mercedes-Benz SIB 272.966/09). Not compatible with lower-tier MB 229.3 or non-approved synthetics.
Emissions: Euro 4 certification applies to pre-2010 models only (VCA Type Approval #VCA/EMS/9012). Euro 5 compliance confirmed for 2010–2015 models in EU markets.
Power Ratings: Measured under ECE R85 standards. Output remains consistent across fuel grades meeting 95 RON minimum (Mercedes-Benz TIS A172001).
Mercedes-Benz Technical Information System (TIS): Docs A172001, A172105, A172200, SIB 272.966/09
VCA Type Approval Database (VCA/EMS/9012)
ISO 8855:2011 Road Vehicles — Vehicle Dynamics and Chassis Components — Vocabulary
The Mercedes-Benz M272.966 was used across Mercedes-Benz's W211/C209/C219 platforms with longitudinal mounting and shared architecture with Mercedes-Benz luxury car initiatives. This engine received platform-specific adaptations-reinforced mounts in the CLS-Class and revised exhaust routing in the CLK-Class-and from 2010 the facelifted W211 models adopted Euro 5-compliant calibration, creating emissions-related interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the front face of the cylinder block near the timing cover (Mercedes-Benz TIS A172001). The 8th VIN digit indicates engine type ('Q' for M272.966). Pre-2010 models have silver cam covers with 'M272' branding; post-2010 units use revised balance shaft assemblies with serial number traceability. Critical differentiation from M272.944: M272.966 is tuned for higher output with revised intake and ECU mapping; M272.944 is standard output. Service parts require model-year verification — balance shaft tensioners for pre-2010 engines are incompatible with post-2010 revisions due to spring redesign (Mercedes-Benz SIB 272.966/09).
The M272.966's primary reliability risk is balance shaft chain tensioner wear in high-mileage applications, with elevated incidence in southern European and Middle Eastern markets. Internal Daimler quality reports from 2011 noted a significant number of pre-2010 engines requiring balance shaft repairs before 150,000 km, while UK DVSA records show auxiliary drive failures as a contributing factor in MOT rejections for vehicles over 10 years old. Infrequent long-distance driving and delayed maintenance increase chain stress, making adherence to 10-year inspection intervals critical.
Analysis derived from Mercedes-Benz technical bulletins (2007–2015) and UK DVSA failure statistics (2015–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M272966.
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