Although the Z3 is basically unchanged for 1998, the aggressive tires and widened rear track that go with the M version lend an even more purposeful look to this car's classic good looks.
The M Roadster has a serious footprint to handle the extra thrust of its potent engine. That footprint also adds up to substantially higher cornering capabilities than the standard Z3, or even the Z3 2.8.
The essential difference between the 1.9-liter and 2.8-liter Z3 roadesters lies under that long, sculpted hood. The 2.8-liter engine is the same aluminum inline-6 used in the 328i coupe and sedan--twin overhead cams and four valves per cylinder. An inline-6 is still the best configuration for quelling primary vibrations--which is why BMW sticks with this design in an age of compact V6s. Both the 2.8- and 3.2-liter 6-cylinder engines are ultra-smooth at all operating speeds.
The 3.2-liter engine in the M Roadster generates great gobs of torque. Torque is really more important than horsepower, because torque is the low-down grunt that most of us use most of the time, whether we're making a stoplight launch or a fifth-gear pass on a two-lane highway. As you'd expect, the M Roadster is very good at sudden squirts of acceleration. Rowing up and down with the excellent 5-speed transmission--Getrag in regular Z3s, ZF in the M model--is part of the driving fun, but the engine's torque band is so broad that fourth and fifth gear can cover a wide range of urban and suburban driving.
A $975 four-speed automatic is available for the 1.9 and 2.8 engines, but the M version is manual only. The automatic operates in three modes--normal, sport, which raises shift points for better acceleration, and winter, which starts the car off in second gear to complement the traction control system (standard) in slippery going.
BMW did a good job of stuffing the extra pair of cylinders under the hood without making a significant change in weight distribution. Balanced at 52 percent front/48 percent rear, good weight distribution is a key element in the Z3's exceptional handling response.
On the downside, more engine means more mass--143 pounds for the 2.8, 361 pounds for the M Roadster. More engine also impacts fuel economy. The 1.9 is rated 23/31 mpg city/highway, the 2.8 is 19/27, the M version, for all its power, scores 20/27. More mass and more power require more stopping power, which the M Roadster supplies with big vented disc brakes all around.
A two-tone interior treatment distinguished the M version from the other two Z3s. Simplicity is a good thing and BMW got it right. Major controls are exactly where you'd expect them. Hop in, close your eyes and reach for something--the gearshift, for example. We'll bet your hand will make precise contact first time, every time--something we cannot say about all cars.
Obviously, the Z3 is a two-seater, and two-seaters are snug by design. This is the kind of car you wear like a finely tailored garment. Even so, there is plenty of legroom and enough headroom under the beautifully crafted soft top for drivers well over six feet.
Fit and finish are superb, inside and out, and the seats provide the kind of lateral support that's required for enthusiastic cornering as well as the kind of contours and padding that go with all-day comfort.
If there are any faults to be found, they are the plastic rear window, which will inevitably become clouded and creased over time, and the diminutive trunk, the price of the Z3's classic sports car styling. Fortunately, the rear window zips out for easy replacement, and the small trunk is a reasonable tradeoff for one of the best-looking sports cars going. And it's easy to live with when there's another car in the driveway.
All three Z3 models come with a manual top that's easy to operate. We were able to flip it open from the driver's seat with one hand. Buttoning up is just as easy.
For all its handling precision and quick response, the dynamic trait that impressed us most about the original Z3 was its ride quality. Like all of BMW's recent offerings, it managed to blend sports car reflexes with a supple ride that took the harshness out of small potholes and pavement patches while leaving the driver connected to the road.
During a couple days of white-knuckle barnstorming on mountainous country roads around Spartanburg, we were surprised to find that the M Roadster has this same quality. Driving through the Blue Ridge mountains gave us little time to think about ride quality, however.
For the most part, our driving sessions became a blur of braking, downshifting, and switchbacks, and we emerged even more impressed with how well the M Roadster accommodated our every whim. Perhaps its most endearing trait, sheer go-power notwithstanding, is its margin for error. This car inspires confidence and forgives mistakes--a great combination for a sports car.
Part of this is the massive grip of its huge tires, but part of it lies in rear suspension tuning that's actually a bit softer than the 2.8. As a result, the M version doesn't feel quite as nervous in quick maneuvers at a brisk pace. Enter a decreasing radius turn a little too quick and the M Roadster seems to give the driver just a little more time to do something about it.
And if that something happens to be stopping, this is the right setup. The stopping power that goes with the wheel and tire package on our M Roadster was nothing short of raceworthy, even when we found ourselves approaching corners at an eye-widening pace. The brakes seem virtually immune to fade--loss of performance in repeated hard applications--no matter how hard or how often they're applied.