The 2015 artfully blends the sportiness of a roadster and the comfort for of a compact luxury car into one handsome package. It may not be quite as sharp as some of its competitors, but it also doesn't make the compromises that other cars must in order to be fun behind the wheel. In short, it's quick, pleasant, and civilized.
Opt for the M Sport Package (it's standard for the sDrive35is) and you'll find confident, quick cornering and direct if not quite intuitive steering. It's a more muted feel than you'll find in, say, an M3, but the Z4 delivers well on its grand touring mission. Without the package, the Z4 is much softer, but it still manages to entertain. One caveat: the run-flat tires on all have stiff sidewalls that can deliver a punishing ride on especially bad pavement even in the base suspension.
Regardless of Z4 model, all have a controlled and balanced chassis that features an adjustable suspension with Comfort, Sport, and finally Sport+ settings.
Three underhood flavors of the Z4 are available: sDrive28i, sDrive35i, and sDrive35is. The first features a urbo, 2.0-liter inline-4 rated at 240 horsepower. The sDrive35i includes a 300 hp, 300 pound-feet of torque inline-6, while the sDrive35is extracts an extra 35 hp and 32 lb-ft.
As you may expect, performance is commensurate with engines: the base Z4 is quick and pretty fun, managing 0-60 mph in a quick 5.5 seconds, BMW says, but in reality it lacks some of the forceful vigor of the 6-cylinder versions.
On the sDrive28is, a 6-speed manual gearbox comes standard. It's an excellent transmission in BMW's tradition. An optional 8-speed automatic fires off shifts quickly, but it dulls some of the Z4's spirited feel. For the Z4 sDrive35i, the 8-speed automatic is replaced with a 7-speed dual-clutch transmission, and the manual transmission has been removed for 2015. The dual-clutch shifts faster than a human can, but it doesn't quite match the race-level crispness and near-telepathic logic of Porsche's PDK unit in the Boxster.