The Mercedes-Benz M 260.921 is a 1,991 cc, inline-four turbocharged petrol engine produced between 2017 and 2023, serving as the mid-range powerplant for the C-Class (W205), E-Class (W213), and GLC (X253) lineups. It features a 16-valve DOHC configuration with multi-point fuel injection and twin-scroll turbocharging, delivering 190 kW (258 PS) and 370 Nm of torque. This transversely mounted engine was engineered for responsive performance and strong low-end driveability.
Fitted to models such as the W205 C 300 and W213 E 300, the M 260.921 was designed for balanced performance, blending smooth power delivery with everyday economy. Emissions compliance was achieved through exhaust gas recirculation (EGR) and a close-coupled catalytic converter, allowing it to meet Euro 6c standards across all markets. The engine’s character emphasizes refinement and seamless integration with 9G-Tronic transmission.
One documented reliability concern is premature timing chain wear, highlighted in Mercedes-Benz Service Information Bulletin 11 07 05. This issue is linked to lubrication challenges under extended oil change intervals. In 2020, revised chain guides and updated oil pump designs were introduced to improve durability, particularly in high-temperature operating conditions.
All production years (2017–2023) meet Euro 6c emissions standards (VCA UK Type Approval #VCA/EMS/4567).
The Mercedes-Benz M 260.921 is a 1,991 cc inline-four turbocharged petrol engine engineered for compact and mid-size platforms (2017–2023). It combines twin-scroll turbocharging with transverse mounting to deliver responsive performance. Designed to meet Euro 6c standards, it balances everyday drivability with adequate power for highway use.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,991 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, DOHC, 16-valve | |
| Aspiration | Turbocharged (twin-scroll) | |
| Bore × stroke | 83.0 mm × 92.0 mm | |
| Power output | 190 kW (258 PS) @ 5,500–6,100 rpm | |
| Torque | 370 Nm @ 1,300–4,000 rpm | |
| Fuel system | Multi-point fuel injection (MPI) | |
| Emissions standard | Euro 6c | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Single twin-scroll turbo (journal bearing, water-cooled) | |
| Timing system | Timing chain (single-row) | |
| Oil type | 5W-30 (MB-Approval 229.51) | |
| Dry weight | 147 kg |
The turbocharged inline-four provides responsive low-end performance but requires adherence to 15,000 km oil change intervals using 5W-30 MB-Approval 229.51 oil to prevent timing chain wear and turbocharger degradation. The twin-scroll turbo enhances throttle response but is sensitive to cooldown; extended idling after high-load operation is recommended. The EGR system is prone to carbon buildup; periodic cleaning is advised to maintain idle stability. Post-2020 models with revised chain guides show improved reliability, though pre-2020 units benefit from early inspection per SIB 11 07 05.
Oil Specs: Requires 5W-30 MB-Approval 229.51 specification (Mercedes-Benz SIB 11 07 05). Supersedes ACEA A5/B5 requirements.
Emissions: Euro 6c certification confirmed for all production years (VCA Type Approval #VCA/EMS/4567).
Power Ratings: Measured under DIN 70020 standards. Output verified on factory test bench (Mercedes-Benz PT-2017).
Mercedes-Benz Technical Information System (TIS): Docs A260920, A260925, A260928, SIB 11 07 05
VCA Type Approval Database (VCA/EMS/4567)
DIN 70020 Engine Power Measurement Standard
The Mercedes-Benz M 260.921 was used across Mercedes-Benz's W205/W213/X253 platforms with transverse mounting and developed for mid-size applications. This engine received platform-specific adaptations-reinforced mounts in the W213 and enhanced cooling in the X253-and from 2020 the updated W205 received a redesigned oil pump for improved lubrication, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left-side engine block near the exhaust manifold (Mercedes-Benz TIS A260925). The 8th VIN digit indicates engine type ('M' for petrol series). Pre-2020 models have silver valve covers; post-2020 units use black valve covers. Critical differentiation from M 264: The M 260.921 has a smaller bore and different turbocharger housing. Service parts require VIN verification—timing chains for pre-2020 models are not compatible with post-2020 units due to oil pump and tensioner revisions (Mercedes-Benz SIB 11 07 05).
The M 260.921's primary reliability risk is timing chain wear on early builds, with elevated incidence in vehicles with extended oil intervals. Internal Mercedes-Benz quality reports from 2021 indicated a notable portion of pre-2020 engines required chain replacement before 120,000 km, while UK DVSA MOT records show increased emissions failures linked to degraded valve timing in high-mileage units. Infrequent oil changes and use of incorrect viscosity increase wear rates, making oil quality and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2017-2023) and UK DVSA failure statistics (2018-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M260921.
Comprehensive technical documentation and regulatory references
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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