year a four-cylinder BMW engine will return to the U.S. in turbocharged formed, first in the 2012 BMW X1 sDrive28i and eventually the 1 and 3-Series models and even the Z4 Roadster.
However, overseas, BMW has been selling a number of four-cylinder engines for some time now, both in naturally aspirated and turbocharged forms, as well as in turbodiesel guise.
Now, a new report claims that BMW plans to eventually add turbocharging technology to its entire range of four-cylinder engines. The most powerful application will be the 245 horsepower unit with TwinPower Turbo technology--BMW's name for its engines equipped with a twin-scroll turbocharging system, direct fuel injection and solenoid injectors.
For any model requiring more than 245 horsepower, BMW will reportedly stick with a six-cylinder or V-8 engine.
The new turbocharged four-cylinder engine lineup is expected to feature 2.0-liter aluminum blocks, with different power outputs coming by way of varying turbocharger technologies and engine mapping. One innovation of the new engine design is said to be a thin 0.3 mm sprayed-on iron cylinder lining instead of the current 1.5 mm cast iron liners.
BMW claims that its new turbocharged four-cylinder engines with TwinPower Turbo technology produces similar horsepower but more torque than its current naturally aspirated six-cylinder engines, as well as fewer emissions.