The most reliable BMW engines by the numbers
BMW's best engines are among the finest internal combustion engines ever mass-produced. The straight-six is BMW's signature — and the data confirms it. From the M50 to the B58, BMW's inline sixes consistently dominate reliability rankings.
Complete ranking
| Rank | Engine | Score | Verdict |
|---|---|---|---|
| 1 | S58 | 89/100 | BEST |
| 2 | B58 | 89/100 | BEST |
| 3 | M43 | 89/100 | BEST |
| 4 | M50/M52 | 86/100 | BEST |
| 5 | M54 | 86/100 | BEST |
| 6 | S68 | 84/100 | BUY |
| 7 | B48 | 82/100 | BUY |
| 8 | B57 | 82/100 | BUY |
| 9 | B37 | 81/100 | BUY |
| 10 | N52 | 81/100 | BUY |
| 11 | B38 | 80/100 | BUY |
| 12 | B47 | 80/100 | BUY |
S58 — 89/100
3.0L Twin-Turbo M I6
Found in: M2, M3, M4
Even the best engines have some issues to watch:
- Coolant loss from cooling system leaks — severity minor, typically appears around N/A
- Early spark plug and ignition coil wear on hard-driven or tuned cars — severity minor, typically appears around 30.000 km
- Crankcase ventilation (PCV) valve wear - valve cover replacement — severity moderate, typically appears around 80.000 km
B58 — 89/100
3.0L Turbo I6
Found in: 1 Series, 2 Series, 3 Series, 340i, 4 Series, 440i, 5 Series, 540i
Even the best engines have some issues to watch:
- Oil pump plastic ring cracks — oil pressure loss (2018-2022 engines) — severity high, typically appears around 48.000 km
- Crankshaft guide bearing wear — early manual F30 340i (service action) — severity minor, typically appears around N/A
- Oil filter shears off in its housing — severity minor, typically appears around N/A
M43 — 89/100
M43 1.6/1.8/1.9 NA I4
Found in: 3 Series
Even the best engines have some issues to watch:
- DISA intake valve failure — severity minor, typically appears around N/A
- Hydraulic lifter clatter — severity minor, typically appears around N/A
- Oil leaks - valve cover, front cover gasket and crankcase vent valve — severity minor, typically appears around N/A
M50/M52 — 86/100
2.0-2.8L NA I6
Found in: 3 Series, 320i, 325i, 328i, 5 Series, Z3
Even the best engines have some issues to watch:
- Nikasil cylinder-bore wear (M52 built 1995 to March 1998, non-US) — severity critical, typically appears around 48.000 km
- VANOS oil seal wear (M50TU from 1992, M52, M52TU) — severity minor, typically appears around 120.000 km
- Valve cover / oil pan gasket leaks — severity minor, typically appears around 150.000 km
Full M50/M52 reliability report →
M54 — 86/100
2.2-3.0L NA I6
Found in: 3 Series, 320i, 325i, 330i, 5 Series, X5, Z3, Z4
Even the best engines have some issues to watch:
- Camshaft / crankshaft position sensor failure — stalling, rpm hunting — severity minor, typically appears around N/A
- Oil leaks — valve cover, oil filter housing and oil pan gaskets — severity minor, typically appears around N/A
- Cooling system plastics — water pump, thermostat, expansion tank — severity moderate, typically appears around 97.000 km
S68 — 84/100
S68 4.4 V8 Twin-Turbo
Found in: 7 Series, M5, X5, XM
Even the best engines have some issues to watch:
- Exhaust-to-catalyst fasteners not tightened (recall, 2023 X7 M60i / XM) — severity minor, typically appears around N/A
Generated from EngineScope's reliability database. Reviewed by the editorial team. Methodology →