A comprehensive matrix of every Mercedes engine code and the chassis it was fitted to. Use this guide to identify which engine is in your car, confirm compatibility for replacement, and decode Mercedes engine codes with confidence.
The Mercedes fitment matrix is your definitive reference for engine-to-chassis compatibility. Every Mercedes model is designed for a specific set of engine codes – the wrong engine won't fit, won't talk to the ECU, and will cause MOT and insurance issues. This matrix lists every major engine family, the chassis codes it was fitted to, and the models you'll find it in.
Scroll down for the full matrix, or use the table of contents to jump to the identification guide.
This table lists every major Mercedes engine family, the chassis codes it was fitted to, the key models, and the number of quote requests we received in 2025. Use this as your starting point for any fitment query.
| Engine Code | Type | Displacement | Chassis Codes | Key Models | EM Requests 2025 |
|---|---|---|---|---|---|
| OM651 | Diesel | 2.1 L | W204, W205, W212, W213, X253, W447, W906 | C‑Class, E‑Class, GLC, Sprinter | 1,250 [EM‑VERIFIED] |
| OM654 | Diesel | 2.0 L | W205, W206, W213, W214, X253, X254, V167 | C‑Class, E‑Class, GLC, GLE | 520 [EM‑VERIFIED] |
| OM642 | Diesel | 3.0 V6 | W211, W212, W164, W166, X204, W251, W906 | E‑Class, ML/GLE, GLK, Sprinter | 880 [EM‑VERIFIED] |
| OM646 | Diesel | 2.1 L | W204, W211, W906 | C‑Class, E‑Class, Sprinter (pre‑2010) | Not in top 62 |
| OM656 | Diesel | 2.9 L | W213, W222, W223, V167 | E‑Class, S‑Class, GLE | Not in top 62 |
| OM611/613 | Diesel | 2.2 L | W203, W211, W906 | C‑Class, E‑Class, Sprinter | Not in top 62 |
| OM640 | Diesel | 2.0 L | W168, W169, W245, W414 | A‑Class, B‑Class, Vaneo | Not in top 62 |
| OM617 | Diesel | 3.0 L | W123, W126, G‑Class (1980s) | E‑Class, S‑Class, G‑Class | Not in top 62 |
| M276 | Petrol | 3.0 V6 | W212, W213, W166, C218, X166 | E‑Class, CLS, GLE, GLS | 390 [EM‑VERIFIED] |
| M274 | Petrol | 2.0 L | W205, W213, X253 | C‑Class, E‑Class, GLC | Not in top 62 |
| M272 | Petrol | 3.5 V6 | W203, W204, W211, W164, X204, C219, R171, W221 (early) | C‑Class, E‑Class, ML, GLK, CLS, SLK, S‑Class | Not in top 62 |
| M270 | Petrol | 2.0 L | W176, W246, X156 | A‑Class, B‑Class, GLA | Not in top 62 |
| M177 | Petrol | 4.0 V8 Biturbo | W205, W213, W222, X166, V167 | C63, E63, S‑Class, GLE/GLS AMG | 370 [EM‑VERIFIED] |
| M157 | Petrol | 5.5 V8 Biturbo | W212, W221, W222, X166, C218 | E63, S63, GLE63, CLS63 | Not in top 62 |
| M156 | Petrol | 6.2 V8 | W204, W212, X164, W463 | C63, E63, ML63, G63 | Not in top 62 |
| M178 | Petrol | 4.0 V8 Biturbo | C190, R190, W463, X290 | AMG GT, G‑Class, AMG GT 4‑Door | Not in top 62 |
| M275/M279 | Petrol | 5.5/6.0 V12 | W220, W221, C216, R230 | S600, CL600, SL600 | Not in top 62 |
| M120 | Petrol | 6.0 V12 | W140, R129 | S600, SL600 | Not in top 62 |
| M112 | Petrol | 2.8/3.2 V6 | W203, W210, W211, W163 | C‑Class, E‑Class, ML | Not in top 62 |
| M113 | Petrol | 5.0 V8 | W211, W220, W163, R230 | E‑Class, S‑Class, ML, SL | Not in top 62 |
| M111 | Petrol | 2.0 L | W202, W203, W210 | C‑Class, E‑Class (pre‑2005) | Not in top 62 |
| M104 | Petrol | 2.8/3.2 Inline‑6 | W124, W140, R129 | E‑Class, S‑Class, SL (1990s) | Not in top 62 |
| M103 | Petrol | 3.0 Inline‑6 | W124, W126 | E‑Class, S‑Class (1980s) | Not in top 62 |
| M102 | Petrol | 2.0/2.3 L | W201, W124 | 190E, E‑Class | Not in top 62 |
| M117 | Petrol | 5.0 V8 | W126, R107 | S‑Class, SL (1980s) | Not in top 62 |
| M133 | Petrol | 2.0 L | W176, W177, X156 | A45 AMG, CLA45 AMG, GLA45 AMG | Not in top 62 |
| M256 | Petrol | 3.0 L | W213, W222, V167 | E‑Class, S‑Class, GLE | Not in top 62 |
| M264 | Petrol | 2.0 L | W205, W213, X253 | C‑Class, E‑Class, GLC | Not in top 62 |
| M282 | Petrol | 1.3 L | W177, X247 | A‑Class, GLB | Not in top 62 |
| M136 | Petrol | 1.3 L | W176, W246 | A‑Class, B‑Class | Not in top 62 |
| M137 | Petrol | 5.8 V12 | W220, C215 | S‑Class, CL | Not in top 62 |
This matrix is based on factory fitment data and verified against our proprietary enquiry database. For full specification details, visit each engine's Knowledge Centre. For a visual representation, see the M272 vs M276 comparison or the OM642 vs OM651 guide.
Use the matrix above to narrow down the possibilities, but to confirm the exact engine code, follow these steps:
Open the bonnet and locate the sticker on the timing cover or camshaft cover. The code will be clearly marked (e.g., OM651, M276, etc.). For older models, the code may be stamped on the cylinder block.
The 8th character of your VIN often indicates the engine family. Use our free Mercedes VIN decoder for a full breakdown.
The engine number is listed on the registration document. Cross‑reference with our Engine Code Guide.
If you cannot locate the code, a vetted Mercedes specialist can identify it during a service or inspection.
Installing the wrong engine is one of the most expensive mistakes you can make. Here's why getting the code right is non‑negotiable:
Once you've confirmed the engine, you can check replacement costs and use the repair vs. replace calculator to make an informed decision.
Even experienced owners sometimes confuse similar codes. Avoid these pitfalls:
If you are unsure, use the OM vs. M‑series identification guide or contact a specialist.
The easiest method is to check the 8th character of your VIN. Use our VIN decoder to get a full breakdown. You can also look at the V5C registration document, which lists the engine number – the engine code is usually the first part of that number.
"OM" stands for Öl-Motor, which is German for oil engine – i.e., diesel. "M" stands for Motor and is used for petrol engines. This naming convention has been in place for decades.
Only if the engine code is listed for your chassis in the matrix above. For example, an OM651 from a W204 C‑Class will also fit a W212 E‑Class or X253 GLC, but you must check the specific variant and ECU compatibility. Always consult a specialist before buying.
Based on our 2025 enquiry data, the OM651 2.1 diesel is the most requested, with 1,250 quotes [EM‑VERIFIED]. It appears in the C‑Class, E‑Class, GLC, and Sprinter. The OM642 V6 diesel follows with 880 requests.
Costs vary widely. A reconditioned OM651 supply‑only is around £2,800–£4,800, while an OM642 V6 is £3,200–£5,500, and an M276 petrol V6 is £3,800–£6,500 [EM‑QUOTE]. See the replacement cost guide for a full breakdown.
If the cost of a replacement engine (supply + fitting) exceeds approximately 70% of your car's current market value, it may be more economical to scrap the car. This threshold is a genuine guideline based on our proprietary data. For worked examples, see the repair/replace/scrap framework.
Knowing your engine code and its fitment is the single most important step before ordering a replacement, checking compatibility, or even diagnosing a fault. Use this matrix to identify your engine, then confirm with the VIN decoder and the Engine Code Guide.
Once you have confirmed the correct engine, the next step is to understand the cost. Visit the replacement cost guide and use the repair vs. replace calculator to make a financially sound decision.
Check Your Engine with Registration LookupReady to identify your engine or get a quote? Compare prices from vetted Mercedes specialists.