BMW automotive engine families listed as M40. Specifications below retain the source's separate family and variant labels.
Family specifications
BMW M40 engine
| Field | Reported value |
|---|---|
| Manufacturer | BMW |
| Production | 1987–1994 |
| Configuration | Naturally aspirated straight-4 |
| Displacement | 1.6 L (1,596 cc) 1.8 L (1,796 cc) |
| Cylinder bore | 84 mm (3.31 in) |
| Piston stroke | 72 mm (2.83 in) 81 mm (3.19 in) |
| Cylinder block material | Cast iron |
| Cylinder head material | Aluminium |
| Valvetrain | SOHC |
| Fuel system | Fuel injection |
| Management | Bosch Motronic 1.3 or 1.7 |
| Fuel type | Petrol |
| Cooling system | Water cooled |
| Predecessor | BMW M10 |
| Successor | BMW M43 |
Variant specifications
Versions
| Version | Displacement | Power | Torque | Year |
|---|---|---|---|---|
| M40B16- E30 version | 1,596 cc (97.4 cu in) | 73 kW (99 PS; 98 hp) at 5,500 rpm | 141 N⋅m (104 lb⋅ft) at 4,250 rpm | 1987 |
| M40B16- E36 version | 1,596 cc (97.4 cu in) | 75 kW (102 PS; 101 hp) at 5,500 rpm | 143 N⋅m (105 lb⋅ft) at 4,250 rpm | 1991 |
| M40B18- E30 version | 1,796 cc (109.6 cu in) | 83 kW (113 PS; 111 hp) at 5,500 rpm | 162 N⋅m (119 lb⋅ft) at 4,250 rpm | 1987 |
| M40B18- E36 version | 1,796 cc (109.6 cu in) | 85 kW (116 PS; 114 hp) at 5,500 rpm | 165 N⋅m (122 lb⋅ft) at 4,250 rpm | 1991 |
BMW automotive engine directory
Design, development and variant notes
Compared with the M10, the M40 adopted a timing belt and hydraulic valve-lash adjustment while retaining an iron block and aluminium head. Wikipedia identifies Bosch Motronic 1.3 on E30 applications and Motronic 1.7 on E36 applications.
The M40B16 and M40B18 use an 84 mm bore with strokes of 72 mm and 81 mm respectively. The M43 progressively replaced the M40.
Variant dimensions and compression
These values are associated with the named variant and source qualifier; equipment and market specifications can differ. A dash means the value is not listed here.
| Variant | Bore (mm) | Stroke (mm) | Compression ratio | Source qualifier |
|---|---|---|---|---|
| M40B16 | 84 | 72 | — | — |
| M40B18 | 84 | 81 | — | — |
Data adapted from the cited Wikipedia revision by Wikipedia contributors under CC BY-SA 4.0. Production dates and fitments reflect that revision; verify the exact engine code, market and vehicle before applying a specification.
Sources
Curated reference notes. Applicability follows the cited sources; hardware testing by this wiki is not implied.
- Wikipedia: List of BMW engines. Wikipedia contributors; CC BY-SA 4.0. Source revision oldid 1382309748; accessed 2026-11-10.
- Wikipedia: BMW M40. Wikipedia contributors; CC BY-SA 4.0. Source revision oldid 1347952073; accessed 2026-11-10.