Belts, chains, and gears: They’ve been the stuff of transmissions for 125 years. But today’s gearboxes have as much in common with the transmission on Henry Ford’s 1896 Quadracycle as your kid’s balsawood glider has with the gone-missing hypersonic Falcon HTV-2.
Today, traditional manuals and torque-converter-equipped automatics share the road with continuously variable transmissions (CVTs), dual-clutch automated manuals, electrified automatics, and power-split electric motor transmissions. And though two- and three-speed automatics and four- to five-speed manuals ruled for decades, new transmissions offer seven, eight and even nine forward gears. As the gear count in new cars approaches double digits, we have to wonder: What’s with the rush for more speeds, and how many is too many?
The Latest Gear Counts
The latest craze amongst manufacturers is the eight-speed automatic transmission. BMW, Audi, Lexus, and Porsche currently offer octo-geared automatic transmissions with traditional torque converters and planetary gearsets. Ford has committed to manufacturing its own eight-speed automatic in-house. Chrysler recently announced it would license ZF-built eight-speeds to pair with the Pentastar V6 as a $1000 option.
But you can always go higher. Fiat/Chrysler CEO Sergio Marchionne says ZF’s new nine-speed automatic could go into new front-wheel-drive offerings beginning in 2013. Mercedes-Benz is known to be developing a nine-speed version of its G-Tronic gearbox to back its AMG performance models.
It’s not just automatics that are seeing the gear count creep ever upward. Manual transmissions have been relegated to either performance or low-price fuel-miser cars in recent years, but even they are seeing the trend. Porsche unveiled its all-new 911 at the Frankfurt auto show, showing off a new seven-speed manual option.