The 2015 Corvette has an all-new eight-speed automatic transmission as an option, designed and built by GM, that is more than 8 pounds lighter and 5% more fuel efficient than the six-speed.
Chevrolet will offer an eight-speed paddle-shift automatic transmission in the Corvette Stingray for 2015. This performance and efficiency upgrade for the hot-selling new sports car that debuted in 2014 was designed and is built by GM in its Toledo, Ohio plant.
Chevy claims excellent shift times that rival the best dual-clutch designs of which ZF is the leading supplier. Porsche, of course, offers dual-clutch automatics and the new Corvette already outperforms Porsche models costing tens – or much more – thousands of dollars greater.
The all-new, GM-designed 8L90 eight-speed is expected to contribute up to 5% more efficiency, when compared to the current six-speed automatic. EPA fuel economy ratings are pending.
This latest improvement makes the Corvette Stingray one of the few sports cars to offer the choice of a conventional manual transmission or an eight-speed automatic.
“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,” says Bill Goodrich, assistant chief engineer for eight-speed automatic transmissions.
The optional 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 6.2-liter naturally aspirated engine.
For aggressive driving, the transmission has full manual control with steering wheel paddles. Chevrolet claims that a new transmission-control system and unique algorithms deliver shift performance that rivals the dual-clutch/semi-automatic transmissions found in many supercars – but with the smoothness and refinement that comes with a conventional automatic fitted with a torque converter.
The transmission controller analyzes and executes commands 160 times per second. 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 an optimal point in the rpm band. This makes the most of the Stingray’s horsepower and torque to improve performance and efficiency.
With four gearsets and five clutches, the packaging allows the new eight-speed automatic to fit the same space as the previous six-speed automatic. Extensive use of aluminum and magnesium make it more than eight pounds, or 4 kg, lighter than the six-speed.
