First Drive: 2007 BMW 335i Convertible
Perhaps the best thing about the new convertible is that it exacts no greater penalty on the driving experience than that of carrying two pals with you in the coupe. The steering is every bit as direct and telepathic, allowing an unfamiliar driver to acclimate right away and explore intuitively the limits of its adhesion. The 335i's 300-horse twin-turbo intercooled engine may have had a bit of tuning since our first encounter last September; we felt no trace of turbo lag, whine, or whistle this time out. That's largely because the blowers are small and tucked away down low in the engine compartment. They serve only to fill in the lower half of the torque curve, achieving their peak boost of about 12 psi almost instantly, and blowing their bypass valves by 3000 rpm. From there on, it behaves like a naturally aspirated 7000-rev engine with 10.2:1 compression.
Finally, please don't revoke our enthusiast licenses for saying so, but the new ZF six-speed automatic might be almost as desirable as the ever-splendid stick. It's vastly preferable to the infuriating SMG box. The secret is its ability to operate with the torque converter locked almost all the time. During sporty driving, lockup occurs right after launch, and shifts are executed with lightning speed (100 milliseconds, or as quickly as the best Ferrari F1 shifts). They're just as firm, too. Order a downshift with the steering wheel paddles (standard on 335i, optional on 328i) and the revs blip. Jam the throttle down, and the optimum gear is selected immediately, without engaging intermediate gears. The converter occasionally unlocks with a noticeable jolt while rolling to a stop, and accelerating from low speeds, where one expects a bit of rubber-banding from the converter, can instead yield a jerky start, but one would quickly get used to this.
Increased computing power, astute hydraulic circuitry, and a patented torsional vibration damper allow Steptronic to offer all the performance and most of the efficiency of SMG and similar automated manuals without the low-speed maneuverability, clunky partthrottle shifts, and other drawbacks. There's room for improvement on the sport-mode automatic-shifting logic, however, which trails the best AMG units in its ability to intuit the perfect gear for every occasion.
With so many great ingredients, this 3 Series cab should age well and be remembered as one of the great vintages-even though it comes with a metal cap.
TECH TIDBITS
Mitsubishi builds the turbochargers, but BMW designed everything from the aerodynamics of their housings to the nickel-alloy steel-turbine wheels.Valvetronic isn't fitted to the 335i because direct-injection and turbocharging provide the same basic benefits.3 Series alternators switch off during acceleration and generate maximum power during coasting and especially braking, like a hybrid's regen feature. An electric water pump runs only as needed, speeding engine and heater warmup, lowering emissions, and improving fuel economy and cooling efficiency. The brake system compensates for fade by increasing line pressures and can hold the car on a hill for 30 seconds. Factory pads have electric wear sensors built in. Radio and GPS antennas are integrated into the rear window and rear side panels. iDrive offers six dash buttons that can be assigned to radio presets, favorite navigation destinations, or quick-dial telephone numbers. A special coating prevents glare on the iDrive screen, which can be viewed at any angle, even with polarized sunglasses.