GM is taking some time to talk about the new 8-speed automatic transmissions that will be offered din the 2015 Stingray and Z06 corvette. The transmissions has a paddle shift feature and despite the fact that it isn't a dual-clutch unit that many enthusiasts hoped for, GM says it shifts very fast.
The 8L90 8-speed automatic transmission has a torque converter and according to GM, at wide-open throttle it can shift faster than the dual clutch unit used in the Porsche 911. GM says that its 8L90 transmission is eight-one hundredths of a second faster at wide-open throttle shifts than the Porsche unit.
That is barely a difference, but the fact that GM's torque converter equipped auto can shift not only as fast, but faster than a Porsche unit is a big deal.
“Corvette Stingray’s new eight-speed automatic delivers the comfort and drivability of a true automatic transmission, as well as lightning-fast shifts and the manual control that enhance the performance-driving experience,” said Bill Goodrich, assistant chief engineer for eight-speed automatic transmissions. “It was designed to enhance the Stingray’s driving experience, with performance on par with dual-clutch designs, but without sacrificing refinement.”
The 8-speed is lighter than the outgoing 6-speed and shod have more fuel efficiency as well. GM says that fuel economy members for an auto car will be announced later. This transmission will be fitted with different gear ratios and a different torque converter in the Z06 than the normal Stingray uses.