While we'd prefer BMW would call it Z4 M (it's a lot easier to pronounce, for one), we're not going to argue with the upgrades to the automaker's twin-turbo 3.0-liter I-6. Mainly through changes to the turbocharger system, the engine now outputs 335 horsepower and 332 lb-ft of torque -- a healthy increase over the 300-hp, 300 lb-ft output in the Z4 sDrive35i. In addition, there's also a controlled overboost function that briefly increases torque by another 37 lb-ft.

The updates to the engine will push the Z4 sDrive35is from 0 to 60 mph in 4.7 seconds on to an electronically limited top speed of 155 mph, according to BMW. The power bump won't come with a corresponding decrease in fuel efficiency, either, as BMW estimates the sDrive35is will roughly match the efficiency of the sDrive35i equipped with the automaker's 7-speed DCT transmission.

Speaking of the DCT, BMW claims both the transmission and the automaker's electric power steering system have been optimized to further enhance the sporting character of the car. In addition, the exhaust system of the Z4 sDrive35is has been fitted with new mufflers and baffles designed to give it a deeper rumble, especially under hard acceleration.

While BMW isn't calling it a Z4 M, the sDrive35is comes with a host of BMW M Sport upgrades. The automaker's adaptive M Suspension for the Z4 is fitted to the car, which features a reduction of overall ride height by roughly a quarter inch, along with a set of electronically controlled shocks. The car's M Aerodynamics kit employs a number of exterior enhancements to the front bumper and rear fascia, and a rear diffuser has been added. Special five-spoke, 18-in. alloy rims are standard equipment, with 19-in. alloys available as an option.

The M treatment continues on the inside, with numerous enhancements including the awesome, thick-rimmed M steering wheel, sport seats, and other model-specific touches including BMW's new Aluminum Carbon interior trim. The sDrive35is also marks the debut of a new leather color called Kansas Walnut, and the car will be available in six colors including Melbourne Red metallic, a new hue for the Z4.