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MANAGING POWER | TRANSMISSION
The manual transmission as we know it—a shifter on the floor and a clutch pedal—is suffering through its death throes. Its competitors? New seven-speed automatics, which improve acceleration over more sluggish versions and adjust shift points to maximize performance; continuously variable transmissions that enhance the power of small engines; and semi-automatic systems that offer the thrill and control of manuals with the ease, when needed, of fully automatic operation.
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Standard equipment in Formula One cars because of their superhuman shift speeds, sequential manual transmissions—which use paddle shifters and an electrohydraulically controlled clutch (no foot pedal)—are now appearing in road-going performance cars.
BMW M3. BMW offers its Sequential Manual Gearbox on its M3 for lightning-quick engagement of its six gears, with several selectable shift programs that allow you to change its demeanor—from easygoing to race-ready.
True sequential manuals are few and far between outside the realm of supercars. The one in the new, $200,000 Ferrari F430 is, well, recommended.
Don’t mistake a manumatic for a sequential manual. Those allow you to shift an automatic transmission at will; an SMG is a manual at heart, complete with robust cogs and a clutch instead of the torque converters and planetary gears found in automatics. These truly are the future of performance driving.
Power 333 hp, 262 lb.-ft. of torque, inline-6 cylinder
Performance 060 in 4.8 sec., 155 mph top speed
Continuously Variable Transmission
A continuously variable transmission (CVT) uses a moving pulley system and a belt or chain to infinitely adjust the gear ratio across a wide range and transfer power between the engine and the wheels.
Ford Freestyle. The CVT helps make the most of the Freestyle’s modest 203 horsepower at all speeds and loads and deliver a respectable combined 22 mpg.
Most hybrids, including the Lexus RX 400h and the Ford Escape Hybrid, use CVTs because their gasoline-engine components are generally smaller than they would be in nonhybrid cars of the same size, making the CVT’s ability to keep an engine in its sweet spot particularly useful.
CVTs can’t yet handle the high torque demands of perfomance cars. Some people are put off by the incessant waaaaa of a CVT that remains at a constant rpm during acceleration and doesn’t give the aural cues they’re used to as the car increases speed.
Power 203 hp, 207 lb.-ft. of torque, V6
Performance 060 in 8.2 sec., 111 mph top speed
Automatic transmissions adjust gear ratios as the car speeds up, so the engine can work at the optimum speed for the task at hand—high revs for power and acceleration, low revs for economy. Better automatics have more gears and adaptive shift maps that adjust based on whether you’re driving vigorously or just cruising around.
Mercedes E350. Mercedes’s 7G-Tronic seven-speed automatic helps improve acceleration by adding shift points—via the additional gears—to give more precise control over how power is applied.
The Range Rover Sport’s transmission is calibrated for both off-road and sporty on-road driving—for example, it won’t upshift if the car is being driven hard through corners.
Ultimately, more gears are better. Each new gear helps to more efficiently put power to the pavement, providing more precise control over the relation between the vehicle speed and the engine speed.
Power 268 hp, 258 lb.-ft. of torque, V6
Performance 060 in 6.5 sec., 130 mph top speed
A variation on the sequential manual gearbox, this technology—currently
available only on Audi and Volkswagen production cars—uses a pair of clutches to cycle through gears, prompted by the computer or the driver, via steering-wheel-mounted paddle shifters. Each gear change takes just two tenths of a second, with no interruption of the torque flow.
Audi A3. The Direct-Shift Gearbox (DSG) is standard in the forthcoming V6 version of the A3 Quattro—a testament to the new technology’s excellent performance.
The DSG transmission is also available in Audi’s sports car, the TT, and the Volkswagen Beetle turbo diesel.
On the road, the DSG shifts noticeably faster and more smoothly than conventional automatics, making for much more spirited driving. If high-speed shifting isn’t appealing, you can order the 2.0-liter A3 with a conventional stick shift.
Power 200 hp, 207 lb.-ft. of torque, inline 4 cylinder
Performance 060 in 6.7 sec., 130 mph top speed
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