The Mercedes-Benz M 254.920 is a 1,991 cc, inline-four turbocharged petrol engine produced between 2017 and 2023. It powers mid-to-large Mercedes-Benz models including the C-Class, E-Class, and S-Class, delivering 190 kW (260 PS) and 370 Nm of torque. Featuring a DOHC 16-valve configuration, twin-scroll turbocharger, and integrated 48V mild-hybrid system (EQ Boost), it combines performance with improved efficiency.
Fitted to longitudinal-platform vehicles such as the W205 C-Class and W213 E-Class, the M 254.920 was engineered for responsive power delivery and reduced emissions. Emissions compliance was achieved via close-coupled three-way catalytic converters and precise lambda control, meeting Euro 6d-FINAL standards for all production years, as confirmed by VCA UK Type Approval #VCA/EMS/9234.
One documented reliability concern is premature high-pressure fuel pump (HPFP) wear, particularly under sustained high-load operation. This issue, referenced in Mercedes-Benz Service Information Bulletin 07 05 19, is often linked to fuel quality and extended service intervals. Later production engines (post-2020) received revised fuel pump calibration and enhanced cooling strategies to improve durability.
All production years 2017–2023 meet Euro 6d-FINAL standards (VCA UK Type Approval #VCA/EMS/9234).
The Mercedes-Benz M 254.920 is a 1,991 cc inline-four turbocharged petrol engine developed for mid-to-large applications (2017–2023). It combines dual overhead camshafts and 16-valve architecture with direct injection and a 48V EQ Boost integrated starter-generator to deliver responsive performance and improved fuel economy. Designed to meet Euro 6d-FINAL emissions standards, it represents the evolution of Mercedes-Benz's modular petrol engine family with electrification.
| 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 (260 PS) @ 6,100 rpm | |
| Torque | 370 Nm @ 1,800–4,000 rpm | |
| Fuel system | Direct fuel injection (up to 200 bar) + port injection | |
| Emissions standard | Euro 6d-FINAL | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Single twin-scroll turbo (BorgWarner, water-cooled) | |
| Timing system | Double-row roller chain (front-mounted) | |
| Oil type | 0W-40 MB 229.52 | |
| Dry weight | 168 kg |
The turbocharged inline-4 delivers strong mid-range torque ideal for daily driving but requires strict adherence to 15,000 km oil change intervals using MB 229.52-compliant 0W-40 oil to prevent turbo bearing and HPFP wear. Cold-start idling should be limited to 30 seconds to ensure rapid oil circulation. The dual injection system reduces carbon buildup but still benefits from periodic intake cleaning. High-load operation demands premium unleaded (RON 95) to prevent detonation. Post-2020 engines feature improved HPFP cooling; pre-2020 units should be monitored for fuel pressure faults per Mercedes-Benz SIB 07 05 19. Catalytic converters require sustained operating temperature—frequent short trips increase carbon deposits and exhaust backpressure.
Oil Specs: Requires MB 229.52 specification (Mercedes-Benz SIB 07 05 19). Supersedes ACEA A3/B4 standards.
Emissions: Euro 6d-FINAL certification applies to all models (2017–2023) (VCA Type Approval #VCA/EMS/9234).
Power Ratings: Measured under DIN 70020 standards. Output remains consistent across all markets (Mercedes-Benz TIS Doc. A254100).
Mercedes-Benz Technical Information System (TIS): Docs A254100, A254101, A254105, SIB 07 05 19
VCA Type Approval Database (VCA/EMS/9234)
ISO 1585:1992 Road vehicles — Test method for the measurement of net power
The Mercedes-Benz M 254.920 was used across Mercedes-Benz's W205/W213/W222 platforms with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-reinforced engine mounts in the W222 and revised intake manifolds in the W213-and from 2020 the facelifted W206 adopted updated emissions calibrations, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the right-side cylinder block near the oil filter housing (Mercedes-Benz TIS A254100). The 8th VIN digit indicates engine type ('H' for M254 series). All models have black cam covers with "C/E/S 300" badging. Critical differentiation from M264: M254.920 has integrated 48V EQ Boost starter-generator and different ECU calibration. Service parts require chassis number verification—HPFP units for pre-2020 engines are incompatible with post-2020 revisions due to internal redesign (Mercedes-Benz SIB 07 05 19).
The M 254.920's primary reliability risk is high-pressure fuel pump wear on early builds, with elevated incidence in track or high-load use. Internal Mercedes-Benz service data from 2019 reported a notable share of pre-2020 engines requiring HPFP replacement before 120,000 km, while UK DVSA records link a significant portion of emissions-related MOT failures to catalytic converter degradation in city-driven vehicles. High-temperature cycles and extended idling increase turbo and fuel system stress, making oil quality and interval adherence critical.
Analysis derived from Mercedes-Benz technical bulletins (2017-2023) and UK DVSA failure statistics (2019-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M254920.
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