The gearless CVT transmission comes and goes in waves of popularity. Previously isolated to European and Japanese-market city cars, they’ve become an aide in the modern quest for fuel-efficient vehicles around the world. Without physical ratios or a torque converter, they’re more efficient than their regular automatic transmission counterparts, but are prone to what’s called the rubber band effect where the engine’s speed rises disproportionately to the speed of the car.
New technology has helped to reduce the negative sides of the CVT, and has allowed it to be used in more powerful applications. One brand that’s capitalized on this is Nissan, which offers CVTs in practically every model it makes, but for its heavy-duty SUVs, trucks and the 350Z sports car. Because of the CVT’s efficiency, all Toyota and Lexus hybrid models use the technology, as does the Honda Civic Hybrid and the Nissan Altima Hybrid. Prestige brands have also worked with CVT gearboxes. Audi’s MultiTronic CVT transmission utilizes a metal link chain for front-wheel drive A4s, while Mercedes-Benz’s A- and B-Class feature a CVT with seven artificially created ratios instead of a conventional automatic.
On the contrary, there are some brands that haven’t been particularly pleased with the results of their CVT transmissions. Ford dropped their ZF-built CVT from the Five Hundred full-size sedan and Freestyle crossover when they made the jump to the Taurus update. Saturn completely discarded CVTs after offering them on the ION and the outgoing VUE. The previous MINI Cooper featured a CVT transmission in place of an automatic, though it’s no longer available.
Now Subaru, one of the quirkiest automakers around, known for their all-wheel drive systems, unique boxer engines and durability, is getting ready to trod down the CVT path once again, according to Winding Road magazine. Having been one of the first to offer a CVT in North America, with its subcompact Justy, it is already a believer in the technologies’ many advantages. The new gearbox would be used in place of a standard automatic, and will be available with most of the mainstream engines that the brand offers. Subaru also hopes to have a CVT available in every car it makes by the year 2010.
Due to the power limitations that CVTs have, we doubt that they’d be featured on the turbocharged 2.5-litre H-4 engine that will move the ultra-powerful Impreza WRX STi, but current CVT technology would still enable it to be used on the less powerful Impreza WRX, Legacy and Forester models. The first Subaru product to feature a CVT transmission is projected to be the 2009 Legacy that is also set for a facelift in that particular model year.
Subaru’s first diesel, a 2.0-litre horizontally opposed engine (a world first for this engine configuration) will be available in North America within the next few years, but the brand hopes on making another world first by mating this new CVT to it. The combination of a high-efficiency diesel engine with a CVT should help make the forthcoming Legacy one of the thriftiest midsize sedans on the market.
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