The new 2.0-liter engine internal code name N20, combines the latest twin-scroll turbocharging technology, high-pressure direct-injection and BMW’s VALVETRONIC intake control. The result is a four cylinder engine that offers more power and torque than BMW’s naturally aspirated 3.0-liter inline six.
The N20 four cylinder turbo engine has a maximum output of 240 horsepower at 5,000 rpm and the 260 ft-lbs of peak torque come on at just 1,250 rpm on 91 octane. When compared to the naturally aspirated 3.0-liter inline six this new four cylinder engine peak power comes on 1,500 rpm sooner and offers 30% more torque.
The four-cylinder engine features a light weight all-aluminum crankcase is lighter and more compact than a six-cylinder engine of equivalent power. The turbocharger is a twin-scroll system. The exhaust streams leaving the two pairs of cylinders are kept completely separate as they flow through the exhaust manifold and the turbocharger, taking a spiral path to the turbine wheel. This configuration results in very low exhaust back pressure at low engine rpm, and allows the energy of the exhaust gas pulses to be optimally managed and translated into powerful rotation of the turbine blades, without a delay in throttle response.
The patented BMW VALVETRONIC system with seamlessly variable intake valve lift control dispenses with the throttle valve system typical of conventional engines. Instead, combustion air mass is controlled inside the engine, resulting in much faster response. Pumping losses are kept to a minimum, making the engine more efficient.
The High Precision Injection direct-injection system also helps to improve efficiency. Centrally positioned between the valves, solenoid injectors with a maximum injection pressure of 200 bar (2,900 psi) precisely control the supply of fuel. The fuel is injected very close to the spark plug, resulting in clean and homogeneous combustion.
The cooling effect of the injected fuel also allows for a higher compression ratio than might otherwise be possible. This results in further efficiency improvements.
US-specific model and timing information will follow at a later date, but this new chapter in the story of BMW EfficientDynamics will arrive later this year.
BMW N20 Motor Type / Qty. Cylinders / Valves Cylinder / Val R / 4 / 4 Motor technology BMW twin turbo technology with power charge after the twin-scroll principle, High Precision Injection, fully variable valve timing, Valvetronic fully variable camshaft control Double VANOS Displacement 1997 cc Stroke / bore 90.1 / 84.0 mm Compaction 10.0 : 1 Fuel RON 91 min Performance 240 hp at speed 5000 rpm Torque 260 ft-lbs at speed 1250 rpm