Call it Z06 trickle-down: the 2015 Chevrolet Corvette Stingray will offer an eight-speed automatic transmission instead of the six-speed automatic currently available. Though a seven-speed manual transmission remains standard, Chevrolet says the new automatic will improve fuel efficiency by about five percent.
The General Motors-developed eight-speed transmission, called 8L90, is based on the one that is optional in the 2015 Chevrolet Corvette Z06 (pictured below). For duty in the regular Chevrolet Corvette, with its 455-460 hp LT1 V-8, the transmission has a unique torque converter and different internal clutches. Clever packaging means the new transmission takes up no more room than the outgoing six-speed offered in the 2014 Chevrolet Corvette Stingray. And the use of aluminum and magnesium in the transmission housing mean the eight-speed is actually eight pounds lighter than the six-speed.
Adding more gears means that automatic Corvettes will be quicker, as Chevrolet says the eight-speed has smaller steps between gears, allowing it to, “keep the engine within the sweet spot of the rpm band, making the most of its horsepower.” As with the current automatic, Chevrolet Corvette drivers can make use of steering wheel-mounted paddles to shift gears manually. Chevrolet says that all full throttle, the new automatic transmission shifts eight-hundredths of a second faster than does the seven-speed PDK dual-clutch transmission in a Porsche 911.
Exact fuel-economy ratings, as well as pricing, for the 2015 Chevrolet Corvette automatic will be announced later. Currently, the Chevrolet Corvette is rated at 16/28 mpg (city/highway) with the six-speed automatic transmission. The sports car achieves 17/29 mpg with its seven-speed manual.