[1]Proving once again that it’s almost impossible to keep a secret in the auto industry [2], GM has confirmed the introduction of an eight-speed automatic transmission in the 2015 Corvette Stingray. This brings the Chevy supercar on par with other competitors in this field, giving the Corvette two extra gears to play with, faster shifting than the Porsche 911, and even better fuel economy. It also means rumors of a delay because of problems with the new transmission were all for naught.
[3]We have previously been warned by the Corvette’s head engineer that there was a lot of work to do to de-tune the eight-speed automatic that debuted in the 2015 Corvette Z06 [4] so it could make its way into regular production Corvettes. With paddle shifters and an upshift that is eight-hundredths of a second quicker than the Porsche 911’s dual-clutch automatic, GM is mighty proud of their new transmission, but fitting it to the less-powerful LT1 engine took some work.
We were worried the new transmission could delay rollout of the 2015 model, or even worse, the 2015 would be saddled with the older and heavier six-speed auto found in 2014 models.
The new eight-speed is a big improvement over the six-speed automatic that is considered old hat in performance car circles. That said, it still managed to deliver an impressive 29 MPG in the 2014 Corvette, even down a couple of gears. With reduced internal friction and two more gears to go through though, GM claims a 5% overall improvement in efficiency, which means faster shifts and more MPG. In the real world, that 5% improvement translates to about 1.5 MPG, which should put the Corvette up over 30 MPG on the highway, and maybe even 20 MPG around town.
More fuel economy, and better performance, and no delays. That’s what we really care about. What more could Corvette buyers ask for?