German Roadsters - BMW Z4 - Comparison

To a large degree, BMW's inline 3.0-liter defines the whole car. The engine is long and partially overhangs the front axle. Driven back to back against the sixes in the Audi and the Porsche, the consequences of the BMW's smooth-running but long crankshaft aren't uniformly positive.

Cruise along at a lazy 2200 rpm, then tip into the power, and the ear-tickling hhhHrRrRrRrR engine note climbs melodically-and lazily. Is the tardiness due to BMW's unusual Valvetronic throttling or the long crankshaft's mechanical inertia? Hard to say, but whatever it is, it plays heck with gear changing as you constantly have to meander the shifter waiting for the revs to catch up, either up- or downshifting. Ironically, this makes for a nice match with the shift mechanism's stubborn notchiness. The Z4 was handily the quickest in a straight line, goading the flat- and V-6 cars with a 5.1-second 0-to-60 dash that bested them by a half-second or more.

That forward-mounted engine also leaves an indelible imprint on handling. A 50/50 weight distribution? Really? According to the scales, perhaps, but bending the BMW into a turn gives you a strong impression of nose-heaviness; angle the wheel, and you'll sense a fraction of a second before the bow gets the message. That's even with our car's Sport Package, which includes 18-inch wheels, grippy Bridgestone Potenza RE050A tires, and firm suspension. Electrically assisted steering was adopted by the Z4 in 2006, and, while we're not pointing any fingers, we've yet to encounter one of these that subjectively equals the old-fashioned hydraulic type.

On the road, the Z4 is one quality chunk of automobile in your hands. In addition to feeling as solid as a block wall, its dash wood is so heavily lacquered it reminds you of one of those glossy wooden windup music boxes, and our car's $1700 optional leather package even coated the sunvisor in precisely stitched hide. Still, all the while you're driving it, you recognize you're doing exactly that-driving it. And it, in turn, is working out its own negotiations with the road. The Boxster isn't like this: Where the Z4 makes the road translucent to the driver, the Boxster makes it nearly transparent.