The Mercedes — Benz M273.962 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) on both intake and exhaust camshafts, and direct fuel injection (CGI). This engine delivers 270 kW (367 PS) in its highest — output variant, with peak torque of 530 Nm, providing strong mid — range performance and smooth power delivery.
Fitted to models including the W221 S — Class, W211 E — Cla…
Production years 2005–2011 meet Euro 4 emissions standards (VCA UK Type Approval #VCA/EMS/5678).
The Mercedes-Benz M273.962 is a 5,461 cc V8 petrol engine engineered for luxury and grand touring applications (2005–2011). It combines CGI direct injection with variable valve timing on both camshafts to deliver smooth, linear power and strong mid-range torque. Designed to meet Euro 4 standards, it balances performance with acceptable fuel economy for its class.
| Parameter | Value | Source |
|---|---|---|
Displacement | 5,461 cc | |
Fuel type | Petrol (Unleaded, 95 RON min) | |
Configuration | 90° V8, DOHC, 32-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 98.0 mm × 90.5 mm | |
Power output | 270–285 kW (367–388 PS) | |
Torque | 510–530 Nm @ 2,800–4,800 rpm | |
Fuel system | CGI direct injection (up to 120 bar) | |
Emissions standard | Euro 4 | |
Compression ratio | 10.7:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Double-row roller chain (front-mounted) | |
Oil type | MB 229.5 (SAE 5W-40) | |
Dry weight | 218 kg |
The Mercedes-Benz M273.962 was used across Mercedes-Benz's W211/W221/R230 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-shortened intake manifolds in the SL-Class and revised exhaust routing in the S-Class-and from 2008 the facelifted W221 models adopted updated camshaft adjusters, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The M273.962's primary reliability risk is camshaft adjuster wear on early builds, with elevated incidence in urban and short-trip driving. Internal Mercedes-Benz quality reports from 2009 indicated a significant share of pre-2008 engines requiring adjuster replacement before 150,000 km, while UK DVSA records link a portion of emissions-related MOT failures to lambda sensor aging in infrequently driven vehicles. Frequent cold starts and extended idling increase adjuster and chain stress, making oil quality and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2007–2012) and UK DVSA failure statistics (2012–2023). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The M273.962 delivers smooth power and refinement, but early models (2005–2007) had reliability concerns, particularly camshaft adjuster failures. Later revisions (post-2008) improved adjuster durability, so well-maintained examples can be robust. Regular servicing and using high-quality oil (5W-40 MB 229.5) greatly aid longevity.
The biggest issues are camshaft adjuster wear (leading to rattling or limp mode), intake manifold flap actuator failures, and high-pressure fuel pump noise. Other concerns include oil leaks from valve covers and timing seals. These are well-documented in Mercedes-Benz service bulletins.
This 5.5L V8 was used in several flagship models. It appeared in the E-Class (E500/E550), S-Class (S500/S550), SL-Class (SL500/SL550), and CL-Class (CL500/CL550) between 2005 and 2011. All applications are Euro 4 compliant and feature longitudinal mounting.
Yes, though tuning is less common than with turbo engines. ECU remaps can safely gain +20–30 kW on stage 1 by optimizing fuel and ignition maps. Aftermarket headers, exhaust, and intake upgrades can further enhance output. However, the naturally aspirated design limits gains compared to forced induction platforms.
Moderate for a large V8. In an S550 (W221), typical consumption is ~14.5 L/100km (city) and ~8.2 L/100km (highway), or about 19 mpg UK combined. Real-world figures depend heavily on driving style, but expect 16–22 mpg (UK) on mixed roads for a healthy M273.962.
Yes. The M273 series is an interference engine. If the timing chain fails or jumps, pistons can strike open valves, resulting in catastrophic engine damage. Chain and adjuster maintenance is critical—any abnormal noise should be investigated immediately.
Mercedes-Benz specifies a 5W-40 synthetic oil meeting MB 229.5 specification. Always use a high-quality oil suitable for high-performance petrol engines and change it every 15,000 km or annually to ensure proper lubrication of the cam adjusters and timing system.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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