The Z4 competes with the Boxster, Corvette, Jaguar F-Type, and Mercedes SLK-Class. The Z4 was redesigned for 2009 and received significant changes for 2012, but there haven't been many updates since then.
The standard engine is a 240-horsepower, 2.0-liter turbocharged four-cylinder, in the Z4 sDrive28i model. Next step up is the Z4 sDrive35i with its 300-horsepower, 3.0-liter turbocharged inline-6. Then there's the Z4 sDrive35is with a 335-horsepower version of that engine, and M Sport suspension tuning for tighter firmer handling.
The base 28i comes with either a 6-speed manual gearbox or 8-speed automatic, while the six-cylinder models come with a 7-speed DCT, or dual clutch transmission.
Driving Dynamics Control is standard, with Comfort, Sport, and Sport+ modes. The dynamic stability control combines traction control, brake fade compensation, start-off assist, brake drying, and brake stand-by features.
The weight of the Z4 hits fuel mileage, although the 28i rates a decent 22/34 miles per gallon City/Highway, for 26 mpg Combined. The 35is, with 95 more horsepower, sucks gas, rating just 20 mpg Combined.
Options BMW Online Portal, real-time traffic information, smartphone BMW apps that enable MOG, Pandora, Aupeo, or Stitcher music streaming and read Twitter and Facebook posts aloud to you. Navigation, satellite radio, and heated seats are optional.
The cabin is sophisticated and upscale, with high quality trim, although the supportive sporty seats are synthetic leather, not the real stuff. The centerstack is somewhat cluttered, but the iDrive control is clean enough.
As with any two-seat roadster, there's not exactly room to spare inside.
The retractable hardtop tucks away neatly, and is so well insulated that the Z4 is nearly as quiet as a coupe inside.
The suspension is designed and tuned to be smooth, so the ride is comfortable. It's a bit soft for the track, although the cornering is stable and fairly well balanced.
If you want sportier handling, there is the M Sport Package (standard on the sDrive35is). It makes the cornering confident, quick, and direct, as the adaptive dampers do much of the work for you. This package includes 18-inch alloy wheels with grippy run-flat tires, which make the ride less comfortable. But it's all a tradeoff, you just have to decide what you want most.
In the sDrive28is, the standard 6-speed manual gearbox is slick and easy, great for those who like to shift. The available 8-speed automatic is quick and smooth, although it steals some spirit from the car.
The sDrive35i and 35is come with a paddle-shifting 7-speed dual-clutch transmission that is the best of both worlds. It's quick, but can't match the racy crispness of the Porsche Boxster's dual clutch.