2007 BMW M Roadster

BMW's "M" series automobiles are built for rabid car enthusiasts who crave power and handling prowess. The Z4 M Roadster is pure, open-air sports car.

A cast-iron 3.2-liter, 24-valve inline six-cylinder engine powers both Z4 M trims. The award-winning M engine features BMW's Double VANOS electronic valve-timing system and the drive-by-wire M Dynamic Driving control, in which each engine cylinder has its own throttle, allowing for more precise engine control. The engine produces 330 hp at 7,900 rpm, with an 8,000-rpm redline and 262 lb-ft of torque, of which 80% is available from 2,000 rpm. Engage the "sport" button, set on the transmission tunnel, and those throttle responses become hyper.

A six-speed manual with closely spaced gear ratios and short gear shift travel takes full advantage of the rev-happy engine. Traveling up through those gears with the heavy-duty clutch, the car blasts across the 0-60 jump in 4.9 seconds, according to BMW (Automobile Magazine got there in 4.8 seconds), with its top end electronically governed to 155 mph. BMW gives 15/22 mpg for fuel economy. CNET's reviewer saw an average of 20.1 mpg for combined city, highway, and freeway driving.

Reviewers credit the Z4 M's straightforward handling style - blast into a corner, stand on the brakes, crank the wheel, hit the gas at the apex, and control the tail's drift with the gas pedal as it blasts out of the corner - with its 2007 M3 underpinnings: stiffer springs, shocks, forged-aluminum front control arms, bushings, and rear suspension.

And for good measure, BMW added the aluminum-hubbed cross-drilled brakes that were intended for the M3 CSL, along with the M3's limited-slip differential (M Variable Differential Lock) that goes a long way in blasting the Z4 M out of those corners. A more-precise hydraulic power steering replaces the electric variety. Further, a Rollover Safety System fits two steel rollbars behind the headrests with a tubular steel rollbar built into the A-pillars.

All reviewers come away with great respect for the Z4 M's free-revving, powerful inline 6 and its drive-at-the-limits style of handling - a sort of a blunt-instrument approach is necessary on the track. But reviewers found the handling enthralling and completely controllable.

The Z4's interior theme is what one might expect in a "true" sports car - simply practical. Edmunds points out that this is a "driver's car" in which the attention is on the road. The M sport seats hold you firmly no matter how far you drift that tail out, and all driving controls are within perfect reach. Interior materials are of higher quality than those on the regular Z4. The fully automatic power soft-top opens and closes in less than 10 seconds at the press of a button.