BMW M20B25 Engine
This page lists the M20B25 specifications for the engine built by BMW.
| Fuel Type | Petrol |
|---|---|
| Configuration | I6 |
| Combustion Type | Naturally Aspirated |
| Displacement (cc) | 2,494 cc |
| Cylinders | 6 |
| Cylinder Bore (mm) | 84 mm |
| Cylinder Stroke (mm) | 75 mm |
| Valves | 12 |
| Valves Per Cylinder | 2 |
| Valvetrain | SOHC |
| Compression Ratio | 8.8:1 |
| Power (kW) | 125 kW @ 5,800 RPM |
| Torque (N⋅m) | 226 N⋅m @ 4,300 RPM |
| Redline (RPM) | 6,500 RPM |
| Weight (kg) | |
| Production | 1985 - 1992 |
Where listed, power output figures are based on the most powerful production variant of that engine, because some manufacturers use different engine maps to tune the same engine for better fuel economy, performance or to differentiate models in the range.
The M20B25 replaced the M20B23 in 1985. It has an upgraded 885 cylinder head.
The first variant of the M20B25 produced between 1985 and 1990 had a compression ratio of 9.4:1 and used a Bosch Motronic 1.1 Engine Fuel Management system. It produced 126 KW of power at 5,800 RPM, 226 N·m of torque at 4,000 RPM. The version of the M20B25 didn't use a catalytic converter.
In 1987, the engine was adapted to use a catalytic converter and the engine management system was replaced with Bosch Motronic 1.3. The compression ratio was reduced to 8.8:1, but with a more sophisticated engine management system, BMW were able to keep the power output almost the same as the previous version. In parts of Southern Europe and other markets where unleaded petrol was not regularly available, the previous version of the M20B25 remained in production until 1990.
Last Updated: 19th October 2020 at 20:40:48