The Mercedes — Benz M 276.821 is a 2,996 cc, V6 petrol engine produced between 2012 and 2017. It features dual overhead camshafts (DOHC), variable valve timing (VVT) on both intake and exhaust, and direct fuel injection with spray — guided combustion. In standard tune it delivered 200 kW (272 PS) and 370 Nm of torque, offering a balance of responsive performance and fuel efficiency for executive and performance applications.
Fitted to key models including the W204 C — Class,…
All models meet Euro 6b standards; 2015–2017 units with cylinder deactivation comply with Euro 6c (VCA UK Type Approval #VCA/EMS/7421).
The Mercedes-Benz M 276.821 is a 2,996 cc V6 petrol engine developed for executive and performance platforms (2012–2017). It combines direct injection with variable valve timing to deliver smooth power delivery and strong mid-range torque. Designed to meet Euro 6b (and select Euro 6c) standards, it balances performance with emissions compliance.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,996 cc | |
Fuel type | Petrol | |
Configuration | 60° V6, DOHC, 24-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 88.0 mm × 82.1 mm | |
Power output | 200 kW (272 PS) @ 6,500 rpm | |
Torque | 370 Nm @ 3,500–5,250 rpm | |
Fuel system | Direct injection (spray-guided, up to 200 bar) | |
Emissions standard | Euro 6b; Euro 6c with cylinder deactivation (2015–2017) | |
Compression ratio | 11.3:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Double-row roller chain with hydraulic tensioner | |
Oil type | MB 229.51 (SAE 0W-40) | |
Dry weight | 184 kg |
The Mercedes-Benz M 276.821 was used across Mercedes-Benz's W204, W212, and W218 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-shortened accessory drives in the W204 and reinforced engine mounts in the W218-and from 2015 the facelifted W212 models adopted revised high-pressure fuel pump drives, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The M 276.821's primary reliability risk is high-pressure fuel pump drive wear on early builds, with elevated incidence in stop-start urban use. Internal Mercedes-Benz quality reports from 2016 indicated a notable share of pre-2015 engines required HPFP replacement before 130,000 km, while UK DVSA records show fuel system-related faults contribute to emissions test failures in city-driven vehicles. Frequent cold starts and extended idling increase torsional stress on the drive mechanism, making oil quality and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2013-2017) and UK DVSA failure statistics (2018-2022). 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 M 276.821 offers smooth performance and good refinement, but early models (2012–2014) are prone to high-pressure fuel pump drive wear. Later revisions (post-2015) feature improved pump drive components and chain dampers, significantly enhancing durability. With regular maintenance and correct oil (MB 229.51 0W-40), well-maintained units can reliably exceed 180,000 km.
The most documented issues are high-pressure fuel pump drive wear (causing stalling and misfires), oil leaks from valve cover gaskets, intake valve carbon buildup, and coolant pump impeller failure. These are confirmed in Mercedes-Benz service bulletins and field reports, with the HPFP issue being the most critical.
This 3.0L V6 petrol was used in several key models: C 300 (W204), E 300 (W212), CLS 300 (W218), and GLK 300 (X204), primarily from 2012 to 2017. It was not licensed to other manufacturers and was succeeded by the M 274 inline-4 in most applications.
Yes, the M 276.821 responds well to ECU remapping, typically gaining 20–30 kW safely. Performance intakes, exhausts, and camshafts can further increase output. However, tuning should not exceed the fuel pump's delivery capacity, and upgraded cooling is recommended for sustained high-load use.
Moderate for a V6. In a W212 E 300, combined consumption is approximately 8.2 L/100 km (34.5 mpg UK), with city driving around 10.5 L/100 km and highway as low as 6.8 L/100 km. Real-world figures depend heavily on driving style, but expect 30–36 mpg UK under mixed conditions.
Yes. The M 276 series is an interference engine. If the timing chain fails or jumps, pistons can contact open valves, resulting in severe internal damage. While chain failure is rare, HPFP drive wear can indicate underlying timing issues, so early diagnosis of stalling or fault codes is essential.
Mercedes-Benz specifies SAE 0W-40 oil meeting MB 229.51 standard. This low-SAPS formulation is critical for protecting the high-pressure fuel pump and hydraulic lifters. Oil changes should be performed every 15,000 km or annually to maintain component longevity and prevent sludge buildup.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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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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