BMW Engine Codes
You may come accross many acronyms and short hand "codes" while shopping for your BMW. One type of code that comes up frequently are the codes to describe the multitude of BMW engine variations. This short list is some of the more common engine code designations you may encounter, and may have installed under the hood of your own BMW. This list is not 100% comprehensive, but does cover most of the common BMW engine codes, the number of cylinders (pistons), some of the models that used that engine, as well as the number of valves (intake and exhaust) on that engine.| Engine Code | # of Cylinders | Engine Size (liters) | Example Models | # of Valves |
| M10 | 4 | 1.6, 1.8, 2.0 | 2002, 318i, 320i | 8 |
| M20 | 6 | 2.0, 2.3, 2.5, 2.7 | 323i, 325i, 325e, 528e | 12 |
| M21 | 6 | 2.4 | 324d, 524td | 12 |
| M30 | 6 | 2.8, 3.0, 3.3, 3.5 | 5, 6 and 7 Series from 1975-1992 | 12 |
| M40 | 4 | 1.6, 1.8 | 316i, 318i | 8 |
| M41 | 4 | 1.8 | E36 318tds | 8 |
| M42 | 4 | 1.8 | 318i, is, ti, Z3 | 16 |
| M44 | 4 | 1.9 | 318i, Z3 | 16 |
| M47 | 4 | 1.9 | 320d | 16 |
| M50 | 6 | 2.3, 2.5, 2.8 | 325i, 525i | 24 |
| M50TU | 6 | 2.3, 2.5, 2.8 | 325i, 525i | 24 vanos |
| M51 | 6 | 2.5 | 325td, 525tds, 725tds | 12 |
| M52 | 6 | 2.8 | 328i, 328is, 528i | 24 vanos | M54 | 6 | 3.0 | X5 E46, Z3, Z4 | 24 Double vanos |
| M57 | 6 | 3.0 | 530d | 24 |
| M60 | 8 | 3.0, 4.0 | 530i, 540i, 730i, 740i, 840Ci | 32 |
| M62 | 8 | 4.4 | 535i, 540i, 735i, 740i, 840Ci | 32 |
| M67 | 8 | 3.9 | 740d | 32 |
| M70 | 12 | 5.0 | 750i, 750iL, 850i, 850Ci | 24 |
| M73 | 12 | 5.4 | 750i, 750iL, 850i, 850Ci | 24 |
| M88 | 6 | 3.5 | M5, M6 | 24 |
| S14 | 4 | 2.3 | E30 M3 | 16 |
| S38 | 6 | 3.5 | M5 | 24 |
| S50 | 6 | 3.0 | E36 M3 | 24 vanos |
| S52 | 6 | 3.2 | E36 M3 | 24 vanos |
| S54 | 6 | 3.2 | E46 M3 | 24 vanos |
| S62 | 8 | 5.0 | E39 M5 | 32 vanos |
| S65 | 8 | 4.0 | E9X M3 (E90/E92/E93 2008+ M3) | 32 double vanos |
| S70 | 12 | 5.6 | 850Csi | 24 |