Automatic transmissions are subject of a bit of arms race of late, specifically concerning the number of transmission gears, as more gears tends to produce greater efficiency. However, Julio Caspari, head of ZF in North America, thinks the maximum number of gears will be reached soon.
Transmission gears have come far in recent years
Ever hear about how manuals are more fuel efficient than automatics? The number of gears was the reason. More gears means the engine stays at lower revolutions per minute for longer, consuming less gas. Manuals typically come with five-speed gearboxes though some sports cars have six.
Automatic transmissions, on the other hand, usually came with four, which has been virtually constant since General Motors introduced the automatic transmission in 1940, on Oldsmobiles, according to the GM Heritage website. It wasn’t until the 1990s when five-speed autos first hit the market and the number of transmission gears has been climbing since. Recently, seven, eight and nine-speed automatics have been introduced, according to AutoBlog, as the efficiency arms race demands. However, the head of a key transmission manufacturer, ZF, thinks the maximum number will soon at hand.
Arms race coming to an end
ZF Friedrichschafen, commonly called ZF, is about to release a nine-speed automatic, 16 percent more fuel efficient than their six-speed. Chrysler, according to AutoBlog, uses ZF’s eight-speed in its vehicles, such as the Chrysler 300, and will also be using ZF’s upcoming nine-speed. Hyundai is said to be close to releasing a 10-speed gearbox and the company already uses a ZF eight-speed in the Genesis Coupe.
[To Get The Utmost Package Deal For A New Ford Visit Gus Johnson Used Cars Here.]
Regarding transmissions, ZF is about as big as it gets. Their six-speed transmission, according to a 2000 article on AudiWorld, was the world’s first. Nearly every major car maker has or currently uses a transmission by ZF, manual and otherwise. However, Julio Caspari, CEO of ZF’s North American division, thinks it isn’t long before the cost ceiling brings the transmission gear race to a close.
According to AutoGuide, he told Automotive News in an interview that the cost of developing transmissions with greater numbers of gears will get too high to justify the gains in efficiency, which will become incrementally smaller. Caspari says the “ideal” transmission, as in an “ideal machine” with 100 percent mechanical efficiency, is only 11 percent more efficient than the company’s eight-speed.
Infinite gears already available
Though Caspari believes a ceiling will soon arrive on the number of gears in an automatic, that’s only for the traditional automatic transmission and, by extension, for manuals and semi-automatics, such as paddle-shifted dual-clutch transmissions.
There is also the continuously-variable transmission, which might not be great for sports cars but certainly are attractive for typical passenger vehicles. The “gears” in a CVT are usually a system of pulleys, which can, due to their design, change shape and alter the output as needed, offering a near-infinite number of gears and maximizing efficiency. Subaru and several other car makers are already offering them.