The Mercedes-Benz M 275.954 is a 5,461 cc, 90° V12 petrol engine produced between 2006 and 2011. It features dual overhead camshafts (DOHC), variable valve timing (VVT) on both intake and exhaust camshafts, and sequential multi-port fuel injection. In standard tune, it delivered 386 kW (525 PS), with torque output of 830 Nm, powering the flagship S-Class and CL-Class models with effortless high-speed performance.
Fitted exclusively to the W221 S-Class and C215 CL-Class, the M 275.954 was engineered for supreme refinement, smooth power delivery, and silent operation at cruising speeds. Emissions compliance was achieved via EGR, three-way catalysts, and OBD-II monitoring, meeting Euro 4 standards across all markets. Its design prioritized low vibration and high torque availability from idle, supporting Mercedes-Benz’s luxury flagship character.
One documented technical update occurred in 2009, addressing early high-pressure fuel pump wear (Mercedes-Benz Service Bulletin 07-2009-01). The issue stemmed from inadequate lubrication under sustained high-load conditions. Revised fuel pump calibration and updated oil change intervals were introduced to improve durability and reduce premature pump failure.
All production years 2006–2011 meet Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/5679).
The Mercedes-Benz M 275.954 is a 5,461 cc V12 petrol engine engineered for ultra-luxury sedan and coupe applications (2006–2011). It combines dual overhead camshafts with variable valve timing on both intake and exhaust to deliver seamless power delivery and exceptional refinement. Designed to meet Euro 4 standards, it balances extreme performance with drivability in top-tier models.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 5,461 cc | |
| Fuel type | Petrol | |
| Configuration | 90° V12, DOHC, 48-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 82.6 mm × 85.6 mm | |
| Power output | 386 kW (525 PS) @ 5,300 rpm | |
| Torque | 830 Nm @ 2,800–3,700 rpm | |
| Fuel system | Sequential multi-port fuel injection | |
| Emissions standard | Euro 4 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | N/A | |
| Timing system | Dual chain (primary and secondary), non-interference design | |
| Oil type | MB 229.5 (SAE 5W-40) | |
| Dry weight | 245 kg |
The naturally aspirated V12 provides linear, vibration-free power delivery ideal for relaxed cruising but requires adherence to 15,000 km oil service intervals to protect the high-pressure fuel pump and hydraulic lifters. MB 229.5 (5W-40) oil is critical due to its shear stability and wear protection for high-load valve train components. Cold-start idling should be limited to 30 seconds to ensure prompt oil circulation. The intake manifold and throttle bodies are prone to carbon buildup after 100,000 km, requiring periodic cleaning to maintain idle stability. Post-2009 models feature updated fuel pumps; pre-2009 units should follow SIB 07-2009-01 for inspection and replacement. Emissions systems rely on precise air metering—faulty MAF sensors can trigger catalyst efficiency codes.
Oil Specs: Requires MB 229.5 (5W-40) specification (Mercedes-Benz SIB 07-2009-01). Compatible with ACEA A3/B4.
Emissions: Euro 4 certification applies to all production years (2006–2011) (VCA Type Approval #VCA/EMS/5679).
Power Ratings: Measured under DIN 70020 standards. 386 kW output applies to S 600 and CL 600 variants (Mercedes-Benz TIS Doc. A001905).
Mercedes-Benz Technical Information System (TIS): Docs A001905, A005905, SIB 07-2009-01
VCA Type Approval Database (VCA/EMS/5679)
ISO 1585:1996 Road vehicles — Test code for net power of internal combustion engines
The Mercedes-Benz M 275.954 was used across Mercedes-Benz's W221/C215 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-intake tuning for the CL-Class and revised engine mounts for the S-Class-and from 2009, updated high-pressure fuel pumps were introduced to improve longevity, creating minor service part differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front-right cylinder bank near the intake manifold (Mercedes-Benz TIS A001905). The 8th VIN digit indicates engine type ('V' for M 275 series). Pre-2009 models have silver valve covers with 'M 275' engraving; post-2009 units use black valve covers. Critical differentiation from M 273: M 275.954 has a 90° V12 configuration with dual chain timing, while M 273 is a 90° V8. Service parts require production date verification—high-pressure fuel pumps before 06/2009 are subject to wear and should be replaced per SIB 07-2009-01.
The M 275.954's primary reliability risk is high-pressure fuel pump wear in pre-2009 builds, with elevated incidence in vehicles with extended oil intervals. Internal Mercedes-Benz quality reports from 2010 indicated a significant number of pre-facelift engines required pump replacement before 120,000 km, while UK DVSA MOT data links a portion of engine-related failures to fuel system neglect. High-load cycles and infrequent oil changes increase pump wear, making oil quality and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2006-2012) and UK DVSA failure statistics (2010-2020). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M275954.
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EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
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UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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GOV.UK: Vehicle Approval
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VCA Certification Portal
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