Fastest, Most Efficient Version of 2015 Corvette Stingray Will Be With All-New Eight-Speed Automatic | Edmunds

Fastest, Most Efficient Version of 2015 Corvette Stingray Will Be With All-New Eight-Speed Automatic

Just the Facts:
  • Chevrolet said today an all-new eight-speed automatic transmission debuting for the 2015 Corvette Stingray will scorch the 0-60 mph run in 3.7 seconds, a tenth of a second faster than with the car's seven-speed manual transmission.
  • The new automatic also allows the 460-horsepower Corvette to generate a rather remarkable highway fuel economy rating of 29 mpg, the same as the manual transmission's rating.
  • Chevy officials also confirmed that the 650-hp 2015 Corvette Z06 will hit dealer showrooms by late December.

MILFORD, Michigan — Chevrolet's 2015 Corvette Stingray coming this fall gets a sophisticated new eight-speed automatic transmission to replace its current six-speed automatic. The brand's engineers confirmed during a race-course introduction at the General Motors proving grounds here that America's sports car will be ever so slightly faster with the new automatic than with the seven-speed manual.

Moreover, the all-new automatic transmission — which also will be fitted to 2015 versions of GM's Chevrolet Silverado and GMC Sierra full-size pickup trucks, as well as its full-size SUVS equipped with 6.2-liter V8s — matches the 29 mpg EPA highway fuel economy rating for the manual-transmission Stingray.

Engineers have assigned an official 0-60 mph acceleration time of 3.7 seconds to the 2015 Corvette Stingray with the eight-speed automatic, while manual-transmission models of the 460-horsepower two-seater make the same run in 3.8 seconds. The automatic-transmission Stingray covers the quarter mile in 11.9 seconds, a tenth of a second quicker than the previous six-speed automatic.

Those are hair-splitting advantages, to be sure, but laps of GM's challenging road-style race course here also underscore the new GM-designed-and-built automatic transmission's performance capabilities with eyeblink-fast manual upshifts that, at full throttle, Chevrolet claims are .08 second faster than the dual-clutch automated manual transmission in the 2015 Porsche 911.

Fuel efficiency for the Corvette Stingray with the new eight-speed automatic also reinforces the car's well-known ability to be surprisingly economical if you want to drive it that way: its combined fuel economy rating is 20 mpg. Several Corvette engineers claim the car is easily capable of highway cruising in the mid-30 mpg range, adding it fractionally missed a 30-mpg highway rating from the EPA. They hint that control-software tweaks in the coming months should win a 30-mpg rating for the automatic-transmission 2016 Corvette Stingray.

The all-new eight-speed automatic, which GM calls Hydra-Matic 8L90, is built at the company's plant in Toledo, Ohio and has one of the highest overall ratio spreads — a broad indicator of overall efficiency — of any current automatic transmission.

The eight gears also enable the transmission to use a more aggressive 1st-gear ratio for quicker acceleration while also enabling a numerically "taller" final drive ratio of 2.41 to maximize fuel efficiency, cutting engine revolutions at 70 mph by 8 percent. 

Meanwhile, Chevy's engineers also revealed that those anxious for the 2015 Corvette Z06 will be able to get their hands on one before year-end. The ultra-performance variant of the Stingray, gunning with 650 hp and 650 pound-feet of torque, will be in dealer showrooms in late December. The car's supercharged 6.2-liter V8, dubbed LS4, is 20 pounds lighter than the previous-generation Z06's engine and is almost exactly the same size as the Corvette's standard 6.2-liter engine.

Edmunds says: No compromises or excuses required for those who decide to go with the 2015 Corvette Stingray's eight-speed automatic transmission.

Leave a Comment