DETROIT—Chevrolet has announced its 2015 Corvette Stingray will be available with an eight-speed paddle-shift automatic transmission.
GM, which designed and built the transmission, says its shift times will “rival the best dual-clutch designs.”
The all-new, GM-designed 8L90 eight-speed is expected to contribute up to 5-per cent greater efficiency when compared to the previous six-speed automatic.
EPA fuel economy test results are pending. GM promises an announcement at a later date.
“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 available 8L90 transmission is based on the same eight-speed automatic that will be offered on the supercharged 2015 Corvette Z06, but with unique clutch and torque converter specifications matched to the torque capacity of the Stingray’s LT1 6.2L naturally aspirated engine.
For performance driving, the transmission offers full manual control via steering wheel paddles. A new transmission-control system and unique algorithms deliver shift performance that rivals the dual-clutch/semi-automatic transmissions found in many supercars.
Wide-open throttle upshifts are executed up to eight-hundredths of a second quicker than those of the dual-clutch transmission offered in the Porsche 911.
Smaller steps between gears, compared to the previous six-speed automatic, keep the engine within the sweet spot of the rpm band, making the most of its horsepower and torque to optimize performance and efficiency.
With four gearsets and five clutches, creative packaging enables the new eight-speed automatic to fit the same space as the previous six-speed automatic. Extensive use of aluminum and magnesium make it about four kilograms lighter than the six-speed.
The 8L90 is built at GM’s Toledo, Ohio, transmission facility.