BMW Faqs

By borrowing parts and technology from the M3 coupe, BMW has turned the Z4 M roadster into the best version of BMW’s small convertible. Previously known simply as the M roadster, the new vehicle has substantially more balanced performance than the base model had.

While BMW is better than most at employing technology in the service of performance, there’s something to be said for getting back to basics, to a car without electric steering, adaptive suspension, active stabilizer bars or the BMW iDrive control system. The Z4 M is in a good position to challenge, though not necessarily beat, the uncomplicated Porsche Boxster S, which is the only model in its price and performance range.

In the BMW M tradition, the Z4 M roadster is something of a sleeper: To the uninitiated, it looks like a regular Z4, albeit a quick one. Many characteristics do distinguish it from the plain roadster, aside from the obvious M badges.

The nose is custom from the hoodline downward. Most obvious are the larger openings below the bumper for engine and brake cooling. In addition, the main grille is blacked out and deeper set than the regular Z4’s. The hood is divided into thirds by two creases that give it a power-bulge look the base model lacks.

BMW didn’t hold back in upgrading the M version’s suspension bits. The front track is wider, and the lower control arms and steering knuckles are exclusive. Around back, the whole subframe is reinforced, and the wheel bearings, stabilizer bar and some of the suspension links are borrowed from the BMW M3 coupe.

The alloy wheels are 18 inches in diameter; mine wore Continental ContiSportContact summer performance tires rated P225/45ZR18 in front and P255/40ZR18 in back. The result of all this hardware is a lower, firmer-riding Z4 with more tenacious handling.

The handling is definitely the best of any Z4, which may seem a foregone conclusion, but I’m not talking about simple grip or reflexes. It just feels more natural. There’s something odd about the Z4 that’s been tough for me to sort out.

Since its debut it has had the “perfect” front/rear weight distribution of 50/50 or thereabouts, yet it always seemed to understeer too much, and the original base 2.5-liter inline-6 didn’t have the guts to overcome it though application of power to the rear wheels.

The engine features continuously variable valve timing and a throttle for each cylinder. This design is the next step in metering precisely the right air-to-fuel mixture. Be it because of the close proximity of these valves to the cylinders or some other provision, the engine’s accelerator response is very quick.

The same could not be said of BMW’s early-generation by-wire throttle, whose lag would have been unacceptable in an econocar. A Sport button changes the sensitivity of the accelerator: When it’s activated, you get more throttle for less pressure on the accelerator.

Drivers acclimate to a specific response, and changing it back and forth seems pointless. Given that a driver is likely to pick one and stay with it, the selection should remain when the car is turned off. As is, it defaults to the non-Sport mode.

BMW says the M does 0 – 60 mph in 4.9 seconds versus the Z4 3.0si’s 5.6 seconds. As shown in the table, the torque peak is low relative to the horsepower, and it comes at a high 4,900 rpm. The car isn’t anemic at low speeds, but the power definitely swells with speed, all the way up to the 7,900 rpm redline. The sound is genteel in normal driving and nice and authoritative under heavy acceleration, though quieter than I expected.

The relatively unadorned interior is typical BMW. Distinguishing attributes include upgraded leather and the option of “extended leather trim” on the doors, pillars, roll bars and center console, as well as exclusive trim packages: Carbon Leather or Walnut Medeira wood.

The manual tilt/telescoping steering wheel does away with the Z4’s silver trim and adds an M logo and matching blue and red stitching. Logos also appear on the head restraints, instrument panel, doorsills and the shifter knob. The shift pattern is backlit at night a very nice touch.

You have to fold yourself a bit to get into the M when the top’s up, and look out for that high doorsill. Accommodations are good for someone 6 feet tall, but for anyone taller, comfort and visibility are questionable.

Close to the driver’s head, the glass rear window provides a decent view, but the roll bars and head restraint are obstructive, as is the pillar formed by the raised top. Parking can be tricky due to the obstructed view and difficulty judging over the trunk and hood exactly where the rounded body ends.