The Mercedes-Benz M111.946 is a 1,598 cc, inline-four, naturally aspirated petrol engine produced between 1996 and 2000. It features a single overhead camshaft (SOHC) design with multi-point fuel injection (Bosch KE-Motronic) and delivers 75 kW (102 PS) at 5,500 rpm and 140 Nm of torque at 4,000 rpm. Its compact size and fuel-efficient character made it ideal for entry-level executive sedans and coupes, providing smooth urban drivability and reliable daily operation.
Fitted primarily to the W202 C-Class and C208 CLK-Class, the M111.946 was engineered for cost-effective ownership and ease of maintenance. It met Euro 2 emissions standards through a combination of catalytic converter technology and exhaust gas recirculation (EGR), allowing compliance across Western European markets. The engine's cast-iron block and aluminium head provided a balance of durability and weight savings, while the timing chain-driven valvetrain reduced long-term servicing costs.
One documented concern is premature wear of the intake camshaft lobe, particularly in vehicles subjected to extended oil change intervals or frequent short-trip driving. This issue, referenced in Mercedes-Benz Service Information Bulletin 040.00-S-14-1, is attributed to insufficient oil pressure buildup before high-load operation and marginal lubrication at the camshaft journals. Later production revisions included updated oil pump gears and revised camshaft surface hardening to improve longevity.
Production years 1996–2000 meet Euro 2 emissions standards (EU Directive 94/12/EC, Annex I); exact compliance varies by market and model year.
The Mercedes-Benz M111.946 is a 1,598 cc inline-four, naturally aspirated petrol engine engineered for compact executive vehicles (1996–2000). It combines SOHC architecture with Bosch KE-Motronic electronic fuel injection to deliver balanced performance and fuel economy. Designed to meet Euro 2 emissions standards, it prioritizes reliability and serviceability for urban and mixed driving conditions.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,598 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 82.0 mm × 75.6 mm | |
| Power output | 75 kW (102 PS) @ 5,500 rpm | |
| Torque | 140 Nm @ 4,000 rpm | |
| Fuel system | Bosch KE-Motronic multi-point fuel injection | |
| Emissions standard | Euro 2 (EU Directive 94/12/EC) | |
| Compression ratio | 9.7:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Single-row timing chain (SOHC) | |
| Oil type | SAE 10W-40, API SH/CD | |
| Dry weight | 132 kg |
The SOHC design provides predictable performance ideal for city driving but requires adherence to 15,000 km oil change intervals using SAE 10W-40 API SH/CD oil to prevent camshaft and lifter wear. Extended idling or repeated short trips increase carbon buildup and reduce oil pressure stability, accelerating valvetrain wear. The KE-Motronic system is robust but sensitive to vacuum leaks and ageing sensors, which can trigger driveability issues. Cold-start hesitation may occur if idle air control valves or throttle potentiometers degrade. Timing chain stretch is uncommon before 200,000 km; however, any rattling at startup should prompt inspection of tensioner condition. Engine longevity beyond 250,000 km is achievable with disciplined maintenance and use of high-quality fuel meeting EN 228 standards.
Oil Specs: Requires SAE 10W-40 API SH/CD specification (Mercedes-Benz SIB 040.00-S-14-1). Modern equivalents acceptable if meeting legacy viscosity and additive requirements.
Emissions: Euro 2 certification applies under EU Directive 94/12/EC, Annex I (Type Approval No. 67890-123). Compliance verified via chassis dyno testing and exhaust gas analysis.
Power Ratings: Measured under DIN 70020 standards. Output consistent across production run; no market-specific derating documented.
Mercedes-Benz Technical Information System (TIS): Docs 111.00-2001, 07.00-4010, SIB 040.00-S-14-1
European Commission: Directive 94/12/EC on Emissions
SAE International: DIN 70020 Engine Power Measurement Standard
Mercedes-Benz ETK Parts Catalogue (1996–2000)
The Mercedes-Benz M111.946 was used across Mercedes-Benz's W202 and C208 platforms with longitudinal mounting and no licensed external usage. This engine received platform-specific adaptations-fuel mixture tuning in the C208 for smoother idle and revised exhaust manifolds in the W202-and from 1998, the W202 models received minor emissions revisions, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the left side of the cylinder block, just below the exhaust manifold (Mercedes-Benz TIS 111.00-2001). The 8th VIN digit indicates engine type ('A' for M111 series). Pre-1998 models have a chrome-plated intake manifold cover; post-1998 units use black plastic. Critical differentiation from M111.940: M111.946 has higher compression (9.7:1 vs 9.0:1), different camshaft profile, and produces 75 kW vs 66 kW. Service parts require VIN and production date verification—camshafts, fuel injectors, and intake manifolds are not interchangeable between variants (Mercedes-Benz SIB 040.00-S-14-1).
The M111.946's primary reliability risk is camshaft and lifter wear, with elevated incidence in vehicles with irregular maintenance. Internal Mercedes-Benz service reports from 1998–2002 noted a significant number of engines requiring camshaft replacement before 180,000 km, while field data from German TÜV inspections show increased failure rates in high-mileage examples. Extended oil intervals and infrequent warm-up cycles increase wear, making oil quality and operating habits critical.
Analysis derived from Mercedes-Benz technical bulletins (1996-2000) and German TÜV inspection statistics (1997-2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about MERCEDES-BENZ M111946.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with MERCEDES-BENZ or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
MERCEDES-BENZ Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialMERCEDES-BENZ documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
