Just as BMW promised back in February, they have arrived at the 2011 New York Auto Show with the return of a 4-cylinder engine to the US line-up. The first vehicle to benefit from this new engine is the Z4 sDrive28i. This new model will go on sale this fall and will replace the Z4 sDrive30i (pictured).
The new 4-cylinder engine delivers a total of 240 HP at 5,000 rpm and a peak torque of 260 lb-ft at only 1,250 rpm. This power will allow 30% more torque than the inline-six engine and achieves 1,500 rpm earlier.
The 4-cylinder engine features an all-aluminum crankcase and is lighter and more compact than a 6-cylinder engine. The turbocharger is a twin-scroll system. The exhaust streams out in two separate pairs of cylinders, flowing through the exhaust manifold and the turbocharger, then circulating to the turbine wheel.
The new Z4 sDrive28i will be offered with an eight speed automatic transmission and will offer a fuel efficiency gain of approximately 20% over the naturally aspirated engine it replaces.
UPDATE 04/22/2011: Paul Ferraiolo, Manager, Product Planning & Strategy, BMW of North America talks about the new BMW Z4 equipped with a four-cylinder engine. Hit the jump to watch the video.