BMW's Z3 series of sports cars was replaced in 2003 by a longer, wider, all-new Z4 duo. The roadster's styling changed dramatically, though both models had a long hood with the two occupants positioned well to the rear. Electric power steering was a first for BMW.
For 2006, the Z4 receives a thorough mid-cycle freshening. Exterior details have been restyled, while updated transmissions complement a new range of inline-six-cylinder engines. To reflect the new drivetrains, trim levels change from 2.5i and 3.0i to 3.0i and 3.0si. Equipment changes include new 17-inch wheels, a revised electronic stability system and a newly optional headlight cleaning system.
The Z4 coupe, a hardtop variant available midyear, sports front-end styling that's similar to the roadster's. It's available only in 3.0si form.
A high-performance M version packs a larger engine and a track-tuned suspension. It's listed separately in cars.com's Research section.
BMW's two-seater displays a blend of convex and concave surfaces, coupled with deeply sculpted bodysides. The Z4 has more edges, especially at the rear, than its rounded predecessor. For 2006, changes include a larger air dam, new fog lamps and updated taillights.
Featuring a 98.2-inch wheelbase — relatively long for a roadster — the Z4 has short overhangs and a low rearward seating position. The hood is aluminum, and soft-top components are magnesium. Equipped with a heated glass rear window, the top retracts beneath an integrated tonneau cover. Manual operation is standard, but power operation is available. Roll bars are located behind the seats, and the A-pillars are reinforced. Premium and Sport packages are available.
The Z4 coupe incorporates a curvaceous roof that flows seamlessly from the windshield to the stern, ending abruptly ahead of a subtle deck spoiler.
Seventeen-inch wheels wear P225/45R17 run-flat tires. The Sport package adds wider 17-inch wheels on the 3.0i and 18-inch wheels on the 3.0si.
Other than its two-passenger capacity, the Z4's cockpit is completely different from the Z3's. Controls are well spaced on a distinctive dashboard, and they receive upgraded materials for 2006. Full-width dash panels are either wood or brushed aluminum. Simulated leather upholstery is standard in the 3.0i, while the 3.0si gets real leather. An extended leather option in the 3.0si adds upholstery to the windshield frame, sun visors and doors.
Under the Hood
BMW's newest pair of inline-six-cylinder engines are available in the Z4, and both displace 3.0 liters. The 3.0i makes 215 horsepower and 185 pounds-feet of torque, while the 3.0si achieves 255 hp and 220 pounds-feet of torque. Roadsters are available with either engine, but coupes come only with the more powerful motor. Both engines realize significant gains over their predecessors, which made 184 hp (2.5i) and 225 hp (3.0i). A six-speed manual transmission is standard in all Z4s, and a six-speed automatic replaces last year's five-speed automatic. There is no word yet on whether BMW's Sequential Manual Gearbox, which was optional for 2005, will be offered for 2006.
Side-impact airbags, knee airbags and antilock brakes are standard. BMW's Dynamic Stability Control electronic stability system offers improved response to brake fade, panic stops, hill starts and wet-weather conditions. A cutoff switch for the front passenger airbag is included.