Won and GM obviously disagree, since metal belt CVT applications are planned for some General Motors vehicles in 2002. "While this will not be the first CVT on the market," he says, "it is significant that we will be bringing this technology to volume production. So it's important to make sure we've overcome all the hurdles before producing it in high volume."
Won explains that CVTs automatically operate at an infinite number of gear ratios over a wider overall ratio range, which allows the engine to run at its most efficient speeds without sacrificing performance.
This technology offers significant fuel economy improvements while eliminating gear shifts, he says. "In our testing of actual CVT hardware, we've been able to achieve more than 7 per cent fuel economy gains compared to a 4-speed automatic transmission. These fuel economy benefits are achieved without compromising performance due to the CVT's wider overall ratio and its ability to target maximum power output during hard acceleration."
In order to improve performance in higher torque applications, Won says, GMPowertrain is moving to add more ratios beyond four speeds, which will also improve fuel economy.
GM Powertrain last year began producing its first 5-speed automatic transmission, the 5L40-E, which is currently available on some BMW models and is planned for aGM application, likely the replacement model for the Cadillac Catera, by 2002."Instead of packaging it in a vehicle that already exists, the 5-speed transmission will be on an all-new redesign of a GM vehicle, which will give us the best opportunity to really integrate it with the vehicle and make the right decisions to balance customer requirements," Won says. "And beyond 2002, we will be bringing out other 5-speed transmissions."