Z4 is 4.24 m long, 1.79 m wide, 1.29 m tall and has a 2,50 m wheelbase. It is also quite heavy: its weight goes from 1,470 kg to 1,585 kg, from the entry-level version to the most complete. Boot compartment, which holds 310 l with the hard top on its place, is reduced to 180 l when it has to accomodate the hard top inside it.
Z4's weight excess is compensated by its engines, both the traditional six-in-line 3-litre powerplants, both naturally aspirated and with twin turbochargers. The entry-level version, sDrive30i, produces 259 bhp at 6,600 rpm and 298 Nm at 2,600 rpmm, while the strongest, sDrive35i, generates 304 bhp at 5,800 rpm and 407 Nm at 1,400 Nm.
All Z4 versions come with a six-speed manual gearbox. sDrive30i has the option of a six-speed automatic transmission, while sDrive35i may have a seven-speed automated dual-clutch manual transmission, the best option when it comes to performance and lowering fuel consumption.
Handling must be close to perfect, as BMW is used to, since weight distribution is almost 50%/50% in each axle. Both the aspirated engine and the turbocharged have the same speeds: 210 km/h and 240 km/h, electronically limited, if the Sport Kit is installed. Acceleration numbers are the only ones to change. sDrive30i with manual gearbox goes from 0 to 100 km/h in 5.9 s, while sDrive30i with an automatic transmission does the same in 6.3 s. sDrive35i with a manual transmission takes 5.4 s to reach the same speed in the same conditions, while sDrive35i with the dual-clutch seven-speed gearbox accelerates to 100 km/h in 5.3 s.