The Mercedes-Benz M273.963 is a 5,461 cc, V8 naturally aspirated petrol engine produced between 2005 and 2011. It features dual overhead camshafts (DOHC), variable valve timing (VVT), and sequential multi-port fuel injection. In standard tuning, it delivered 225 kW (306 PS) with peak torque of 460 Nm, providing strong mid-range performance for grand touring applications.
Fitted to flagship models such as the W221 S-Class, W211 E-Class, and R230 SL-Class, the M273.963 was engineered for smooth, refined power delivery and long-distance comfort. Emissions compliance was achieved through EGR and a close-coupled three-way catalytic converter, allowing Euro 4 compliance across all production years in European markets.
One documented concern is premature camshaft wear observed in early production units, highlighted in Mercedes-Benz Service Bulletin 273.963-01/08. This issue is linked to inadequate lubrication flow in the variable camshaft adjuster system under extended idle or low-RPM operation. From 2008, revised camshaft adjusters and updated oil pump calibration were implemented to improve oil pressure stability.
Production years 2005–2011 meet Euro 4 standards (VCA UK Type Approval #VCA/EMS/5678).
The Mercedes-Benz M273.963 is a 5,461 cc V8 naturally aspirated engine engineered for luxury and executive vehicles (2005–2011). It combines dual overhead camshafts with variable valve timing to deliver smooth, linear power delivery. Designed to meet Euro 4 standards, it balances high-end performance with drivability and refinement.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 5,461 cc | |
| Fuel type | Petrol | |
| Configuration | 90° V8, DOHC, 32-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 96.9 mm × 92.4 mm | |
| Power output | 225 kW (306 PS) @ 6,000 rpm | |
| Torque | 460 Nm @ 2,700–4,000 rpm | |
| Fuel system | Sequential multi-port fuel injection | |
| Emissions standard | Euro 4 | |
| Compression ratio | 10.7:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Dual chain (primary and secondary), non-interference design | |
| Oil type | MB 229.5 (SAE 5W-40) | |
| Dry weight | 210 kg |
The naturally aspirated V8 delivers linear throttle response ideal for relaxed cruising but requires consistent oil maintenance to prevent camshaft adjuster wear. MB 229.5 (5W-40) oil is essential due to its shear stability and anti-wear additives protecting the variable valve timing system. Extended idling or short-trip driving increases carbon buildup and oil degradation, so 15,000 km service intervals are recommended. The engine's sensitivity to fuel quality necessitates premium unleaded (RON 95 minimum) to maintain combustion efficiency and prevent knock. Post-2008 models feature revised cam adjusters; pre-2008 units should be inspected per Mercedes-Benz SIB 273.963-01/08. EGR and intake manifolds require periodic cleaning to sustain airflow and idle stability.
Oil Specs: Requires MB 229.5 (5W-40) specification (Mercedes-Benz SIB 273.963-01/08). Supersedes ACEA A3/B4.
Emissions: Euro 4 certification applies to all production years (2005–2011) (VCA Type Approval #VCA/EMS/5678).
Power Ratings: Measured under DIN 70020 standards. Output consistent across markets with premium fuel (Mercedes-Benz TIS Doc. A32010).
Mercedes-Benz Technical Information System (TIS): Docs A31275, A31540, SIB 273.963-01/08
VCA Type Approval Database (VCA/EMS/5678)
ISO 1585:1992 Road vehicles — Test code for net power of internal combustion engines
The Mercedes-Benz M273.963 was used across Mercedes-Benz's W211/W221/R230 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-intake manifold tuning in the SL-Class and revised cooling routing in the S-Class-and from 2008 the updated camshaft adjuster system introduced in facelifted E-Class models improved oil pressure response, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front timing cover near the harmonic balancer (Mercedes-Benz TIS A31275). The 7th and 8th VIN digits indicate engine type ('4G' for M273.963). Pre-2008 models have silver cam covers with black plastic intake manifolds; post-2008 units use black cam covers. Critical differentiation from M273.964: M273.963 has a 5.5L displacement and lacks direct injection. Service parts require production date verification—camshaft adjusters before 09/2007 are incompatible with later units due to internal redesign (Mercedes-Benz SIB 273.963-01/08).
The M273.963's primary reliability risk is camshaft wear in early builds, with elevated incidence in urban and low-RPM driving. Internal Mercedes-Benz quality reports from 2009 indicated a significant number of pre-2008 engines requiring camshaft replacement before 150,000 km, while UK DVSA records show intake-related faults contributing to emissions test failures. Extended idling and short-trip usage reduce oil pressure stability, making adherence to oil specification and service intervals critical.
Analysis derived from Mercedes-Benz technical bulletins (2006-2012) and UK DVSA failure statistics (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M273963.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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