It’s no secret that BMW’s been plotting to return a four-cylinder engine to its U.S. lineup post-haste, and we’ve finally seen the first result as BMW debuted the Z4 sDrive28i at the New York auto show today. Though the engine hood release was disabled on the display car, within that yellow snout should reside an all-new 2.0-liter turbocharged four-cylinder engine.
While you might guess that the new four-cylinder Z4 would slot underneath the current naturally-aspirated inline-six in the lineup as a bargain-priced, entry-level model, but we’re wagering that’s not the case. With 240 horsepower and 260 pound-feet of torque, the new turbo-four should be more than a match for the current 255-horse, 220-lb-ft six, especially when considering the four’s lighter weight. The four’s smaller size also allows it to be mounted further back and lower in the Z4′s chassis, providing both better weight distribution and a lower center of gravity. With that in mind, expect the new turbo-four, already slated for the upcoming X1 CUV, to gradually replace the naturally-aspirated six across BMW’s model range.
The new engine is a smorgasbord of BMW’s latest technology, including high-pressure fuel injection, BMW’s proprietary double VANOS variable camshaft control system, and Valvetronic, BMW’s variable valve timing setup. The turbocharger, BMW says, is also an impressive piece, being driven by two exhaust ducts rather than one (hence its TwinPower Turbo name). This technology is partly to thank for the turbo-four’s improved fuel economy over the six, which according to BMW could be a 20-percent improvement. That potentially means a bump from the six’s current 18/28 city/highway mpg rating, to 22/34 mpg. Read the rest of this entry »