Is the S55 reliable?
We rate the S55 72 of 100 for reliability: good. The rating is one of the inputs to every Guide Score below, and it is argued for on the method page with the others.
Why that rating
The lit mark is the S55; each grey mark is another engine on the engines page.
Solid in stock form, and the headline risk is tune-correlated: crank hub slippage on cars pushed past stock power. Rod bearing wear is debated but monitored by the community. Well-documented, manageable, not carefree.
Cars in this guide with the S55
| Car | Years with this engine | Reliability | Guide Score |
|---|---|---|---|
| M2 F87 | 2019 to 2021 | 72 to 73 | 91 (2021) |
| M4 F82 | 2015 to 2020 | 69 to 72 | 84 (2020) |
| M3 F80 | 2015 to 2018 | 69 to 71 | 83 (2018) |
| M4 F83 | 2015 to 2020 | 66 to 69 | 72 (2020) |
Reliability is each car's score out of 100 for the years it had this engine: the engine rating plus that car's own known problems, service costs and age. The Guide Score is for the car's best year to buy.
Known problems on the S55
| Problem | Named in the guides for | Typical bill |
|---|---|---|
| Crank hub slippage | M2 F87 | $4,000 |
Bills are the guides' estimates, not quotes; each car's guide says which model years a problem hits and how to check for it. The bars share one scale, up to the costliest bill here.
Other engines
Every engine we rate, from the most reliable down, is on the engines page.