The most reliable Mercedes-Benz engines by the numbers
Mercedes-Benz's most reliable engines come from two golden eras: the pre-2000 over-engineered classics (OM606, M104, M113) and the modern post-2016 generation (M256, M264). Both share a design philosophy: simplicity where it matters.
Complete ranking
| Rank | Engine | Score | Verdict |
|---|---|---|---|
| 1 | OM612 | 92/100 | BEST |
| 2 | M264 | 89/100 | BEST |
| 3 | M113 | 89/100 | BEST |
| 4 | M256 | 88/100 | BEST |
| 5 | M266 | 88/100 | BEST |
| 6 | M104 | 85/100 | BEST |
| 7 | OM606 | 84/100 | BUY |
| 8 | OM648 | 84/100 | BUY |
| 9 | M111 | 84/100 | BUY |
| 10 | M177 AMG | 84/100 | BUY |
| 11 | OM613 | 84/100 | BUY |
| 12 | M112 | 84/100 | BUY |
OM612 — 92/100
OM612 2.7 CDI I5
Found in: C-Class, E-Class
Even the best engines have some issues to watch:
- Turbocharger wear at high mileage — severity minor, typically appears around 209.000 km
- Injector seal leak (Black Death) — severity moderate, typically appears around N/A
Full OM612 reliability report →
M264 — 89/100
1.5/2.0L Turbo 48V I4
Found in: C-Class, E 200, E 300, E-Class, GLC
Even the best engines have some issues to watch:
- 48V belt starter-generator / 48V battery faults (EQ Boost) — severity moderate, typically appears around 80.000 km
- Thermostat / electric water pump failure — severity moderate, typically appears around 80.000 km
Full M264 reliability report →
M113 — 89/100
4.3-5.5L V8 NA
Found in: C-Class, CLK, E-Class, S 430, S-Class, SL
Even the best engines have some issues to watch:
- Harmonic balancer (crank pulley) rubber delaminates — severity high, typically appears around N/A
- Coolant system: water pump, thermostat, expansion tank — severity minor, typically appears around 100.000 km
- Crankshaft position sensor fails when hot — stall or hot no-start — severity minor, typically appears around N/A
Full M113 reliability report →
M256 — 88/100
3.0L Turbo 48V I6
Found in: AMG GT, E-Class, G-Class, GLC, GLE, GLE 450, S 450, S-Class
Even the best engines have some issues to watch:
- Oil leaks — valve cover / front cover gaskets — severity minor, typically appears around 97.000 km
- Timing chain tensioner wear — unconfirmed — severity minor, typically appears around 129.000 km
- 48V system faults — starter-generator, wiring and battery software (recalls) — severity moderate, typically appears around 64.000 km
Full M256 reliability report →
M266 — 88/100
M266 1.5/1.7/2.0/2.0 Turbo (A-Class W169, B-Class W245)
Found in: A-Class
Even the best engines have some issues to watch:
- Fuel-tank vent line leak - fuel smell (recall, July 2010 builds) — severity minor, typically appears around N/A
- Timing chain and tensioner wear - cold-start rattle (reports disputed) — severity moderate, typically appears around 97.000 km
Full M266 reliability report →
M104 — 85/100
M104 2.8/3.0/3.2 I6 24V
Even the best engines have some issues to watch:
- Engine wiring harness insulation crumbles (cars built about 1993-1995) — severity high, typically appears around 66.000 km
- Head gasket leak with age, usually after overheating — severity high, typically appears around N/A
- Oil leaks (cylinder head, oil-filter housing seals) — severity minor, typically appears around N/A
Full M104 reliability report →
Generated from EngineScope's reliability database. Reviewed by the editorial team. Methodology →