| Manufacturer | BMW, Bayerische Motoren Werke AG |
|---|---|
| Production | 2009– |
| Predecessor | BMW N54 |
| Class | Straight-6 |
The N55 is a turbocharged straight-6 automobile engine from BMW. It was launched in early 2009 in the new BMW 5-Series Gran Turismo in the BMW 535i GT model.[1] It is BMW's first production single turbocharged gasoline engine that combines the use of Valvetronic, turbocharging, Cylinder-bank Comprehensive Manifold (CCM), and direct injection technologies.
| Engine | Displacement | Power | Torque | Redline | Year |
|---|---|---|---|---|---|
| N55B30 | 3.0 L (2979 cc/181 in³) | 225 kW (300 hp) @ 5800 | 400 N·m (300 ft·lbf) @ 1200-5000 | 7000 rpm | 2009 |
| N55B30 | 3.0 L (2979 cc/181 in³) | 225 kW (315 hp) @ 5800 | 400 N·m (330 ft·lbf) @ 1200-5000 | 7000 rpm | 2011 |
The N55 was the first engine to receive the BMW TwinPower Turbo brand name, although it actually uses a single turbocharger, with twin scroll Cylinder-bank Comprehensive Manifold (CCM) technology taking in exhaust pulses from two groups of 3 cylinders. Valvetronic is used to help reduce throttle losses. BMW has also retroactively applied the "Twin Turbo" moniker to earlier engines such as the N54 straight-6 and N63 V8 which have twin turbochargers but not twin scroll technology. The S63 V8 (the high-performance M derivative of the N63) and N74 V12 have twin turbochargers and twin scroll technology.
The N55 has replaced the N54 in many applications as well as supplanting the high output versions of the N52B30. The preceding N54 was a twin-turbocharged straight-6 with direct injection technology that did not use Valvetronic. The N55 has reduced emissions and fuel consumption in keeping with BMW's Efficient Dynamics initiative.[2]
The N55 is mated to ZF's new 8-speed automatic transmission with Steptronic in most applications, though the 2011 BMW 3-Series will instead use the 6-speed automatic with Steptronic, and a 6-speed manual is usually available for cars (sedans, coupes, wagons) but not crossover SUVs. The N55 in the 135i and 335is is instead mated with a 7-speed DCT (dual clutch transmission).
Applications: