All engines
| Code | Family | Era | Protocol | Common models | Verification |
|---|---|---|---|---|---|
| B48 | F/G-series 2.0L turbo I4 | 2015+ | UDS over DoIP | F20/F22 x20i/x30i; G20 330i; G01 X3 30i | 14/22 params verified (64%) |
| B58 | F/G-series 3.0L turbo I6 | 2015+ | UDS over DoIP | F22 M240i; G20 M340i; Toyota GR Supra | 20/22 params verified (91%) |
| N20 | F-series 2.0L turbo I4 | 2011–2016 | UDS over DoIP | F20 125i; F30 328i; F25 X3 28i | 14/22 params verified (64%) |
| N52 | E9x/E60 2.5/3.0L NA I6 | 2004–2013 | KWP2000 | E90 325i/328i; E60 528i; E83 X3 | 9/10 params verified (90%) |
| N54 | E8x/E9x 3.0L twin-turbo I6 | 2006–2013 | KWP2000 | E82 135i; E90 335i; E60 535i | 11/12 params verified (92%) |
| N55 | E9x/F-series 3.0L turbo I6 | 2009–2017 | Mixed | E90 335i; F30 335i; F22 M235i | 24/25 params verified (96%) |
| N57 | F-series 3.0L diesel I6 | 2008–2019 | UDS over DoIP | F10 530d; F25 X3 30d; F32 435d | 21/30 params verified (70%) |
| N62 | E60/E63 4.0/4.4/4.8L NA V8 | 2001–2010 | KWP2000 | E60 540i; E63 645Ci; E53 X5 4.4i | 13/13 params verified (100%) |
| S55 | F80/F82/F87 M twin-turbo I6 | 2014–2021 | UDS over DoIP | F80 M3; F82 M4; F87 M2 Competition | 16/25 params verified (64%) |
| S58 | G80/G82/F97/F98 M twin-turbo I6 | 2019+ | UDS over DoIP | G80 M3; G82 M4; F97 X3M | 14/23 params verified (61%) |
By generation
E-series (KWP2000 / K+DCAN)
- N52 — the most reliable NA inline-6; valve cover gasket (valley pan) is the headline maintenance item.
- N54 — twin-turbo predecessor to the N55. Famous for HPFP and index-12 injector failures.
- N55 — single twin-scroll turbo. Replaced the N54 with a more reliable HPFP, but still direct-injection.
- N62 — 4.0/4.4/4.8L NA V8. Slow-coolant valley-pan oil-leak on higher-mileage cars.
F/G-series (UDS / ENET/DoIP)
- N20 / N26 — 2.0L turbo I4 in late E-series and F-series. Timing-chain stretch on high-mileage cars.
- B48 / B46 — modular B-family 2.0L. Successor to the N20; cleaner emissions, similar service patterns.
- B58 — current 3.0L turbo I6. Charge-pipe boost-leak is the early-production headline.
- N57 — 3.0L diesel I6. DPF and EGR state are the unique diagnostic surface.
- S55 — M3/M4 M twin-turbo. Crank-hub failure is the documented concern.
- S58 — M3/M4 (G-series) M twin-turbo. M-tuned B58 architecture, not N55-derived.
Verification
Each engine profile has a parameter catalog in the project’s community/profiles/<id>.toml. The verification percentage is the ratio of parameters marked verified: true to total parameters. OBD-II mandated PIDs (RPM, coolant, IAT, MAF, load) are emissions-mandated and verified by design — they always count as verified. BMW-specific DIDs and decoder-specific entries are where the verification work is concentrated.
The verification label flips per parameter only via a real-car validation harness report filed against docs/validation/<engine>-real-car.md. The N62 profile is fully verified because every BMW-specific entry has been cross-checked against the OBDb DID database; the N55 profile is nearly fully verified for the same reason. The S55/S58 profiles have lower verification percentages because M-variant-specific DIDs are not as well documented in the OBDb source.
Comparison questions
Which engine is the most reliable?
N52, N62, and N55 are the strongest. The N54 has known HPFP and injector issues; the S55 and S58 are track-duty engines with crank-hub concerns.
What protocol does each engine use?
E-series engines use KWP2000 over K+DCAN. F/G-series engines use UDS over DoIP. The N55 spans both, depending on production year.