The tail of an arctic storm was whacking Los Angeles as I got reacquainted with our Z4 roadster. Previous, short stints in the car had left me indifferent, chiefly because I felt its sequential manual gearbox (SMG) blunted the two-seater's better qualities. SMG's responses to my prompts with the gear lever or paddle shifters felt clunky, particularly on the upshifts, and the "Drive" mode seemed indecisive, hunting for the right gear and often selecting, for me, the wrong one. It all made the SMG far less rewarding than BMW's slick manually operated transmissions.
However, accepting that my lukewarm response to SMG might have been fashioned out of inattention rather than senseless technology, this time around I vowed to focus on the electro-hydraulic system's operation. I even cracked open the owner's manual to see if it might reveal an essential technique to using SMG, turning my balky progress into smooth, Montoya-esque gear selection.
As with many publications of its type, the SMG manual's language is a riot. Consider: "When the speed is reduced, the gearbox is automatically downshifted shortly before a gear-dependent minimum speed is reached without you taking any action." However, while struggling through the challenging syntax, I came upon this tantalizing bit: "The acceleration assistant permits optimum acceleration on skid-resistant roads at a racing-speed level."
Well, even if I wasn't quite sure what that meant, it definitely sounded worth exploring. As instructed, first I activated the "Sport" program via the console-mounted button, then pressed the "DSC" button for more than 3 seconds. Had I not been idling in our underground parking garage, I then would have pressed the accelerator "...all the way down rapidly--kick-down. The optimum rpm for driving off will be adjusted."
Best wait for a skid-resistant road, I concluded, to find out the results of all that optimum rpm. For now, just get to know how to work the damn thing before I started wrecking it. (As one of the few unequivocally clear passages in the manual puts it, "Using the acceleration assistant leads to premature wear of the vehicle's parts since this function places a very high strain on the vehicle.")
So instead I dropped the top, pushbutton quick, enjoying open-air motoring on a cold, blustery day. With the Z4's heated seats and industrial-strength climate control on parboil settings, I need just a light jacket to stay snug on crisp days.
Crisp can also describe the Z4's road manners. Its dohc 2.5-liter six is more than enough to validate the sports car's performance subtext, its smooth power delivery complemented by such expected BMW qualities as a stiff structure, sport-tuned and compliant suspension, excellent brakes and point-and-shoot steering.
Because I'd been driving a string of big and powerful cars, sliding into the Z4 was like slipping back into my favorite b'ball shoes and becoming the fleet-footed guard of my youth. Grip, change of direction, my crossover dribble...it all came back after just a few miles behind the Z4's wheel. And, much to my surprise, SMG now felt a perfect complement to the car's essential BMW qualities. Whether the gearbox was finally "broken in," or my quick study of the owner's manual paid off in ways I had yet to understand, I had an absolute blast using SMG, in all conditions and at all times. Forget "Drive"; it still brings nothing to the feast. Use full sequential mode and the "Sport" program (faster throttle response; electronic steering adjusted for more directness; quicker shifting), and the beauty of SMG emerges from its technical complexity.
Not that SMG suffers the casual driver. Subtle manipulations of the throttle help bring out SMG's best; you just can't push down with your right foot, select a gear and enjoy the rush. Lift off slightly on the upshifts and reapply the gas at just the right moment, and you're suddenly in sixth gear and traffic has been left far behind. I also learned when to shift down; in fact, SMG taught me, with its perfect blips of the throttle and its safeguards against over-revs, just when it was best to execute a lower gear. This was one of those rare cases where I felt in synch with a complex system and not just a slightly befuddled user.
Now, I'm off to that "skid-resistant" road to test out acceleration assistant. I'll let you know if I break anything.