2015 Chevrolet Corvette Gets Eight-Speed Automatic, Rated At 29 MPG Highway

2015 brings a big change for the Chevrolet Corvette Stingray as the six-speed automatic transmission says adiós and the eight-speed automatic says hello. The new eight-speed features a more aggressive first gear ratio and lower rear axle ratio. This allows the 0-60 MPH time to drop from 3.8 to 3.7 seconds and a improved quarter mile time of 11.9 seconds (times are for the Corvette Stingray equipped with the Z51 package).

Fuel economy also sees a slight bump with Corvette Stingray now getting 29 MPG on the highway. City and combined numbers are still the same (16 and 20 MPG respectively).

"The Corvette Stingray is a great example of how we are leveraging engineering and technology to improve both efficiency and performance. No other car can match 460 horsepower, 0-60 mph in better than 3.7 seconds, and 29 mpg on the highway," said Mark Reuss, GM executive vice president, Global Product Development, Purchasing & Supply Chain in a statement.

Source: Chevrolet

William Maley is a staff writer for Cheers & Gears. He can be reached at[email protected]or you can follow him on twitter at @realmudmonster

Press Release is on Page 2

8-Speed Automatic Makes Corvette Faster, More Efficient

DETROIT – The all-new, paddle-shift eight-speed automatic transmission makes the 2015 Corvette Stingray faster and more fuel efficient, with 0-60 acceleration of only 3.7 seconds and an EPA-estimated 29 mpg on the highway.

"The Corvette Stingray is a great example of how we are leveraging engineering and technology to improve both efficiency and performance," said Mark Reuss, GM executive vice president, Global Product Development, Purchasing & Supply Chain. "No other car can match 460 horsepower, 0-60 mph in better than 3.7 seconds, and 29 mpg on the highway."

The Stingray's 0-60 performance is 0.1-second quicker than the previous six-speed automatic, contributing to a quicker quarter-mile elapsed time of 11.9 seconds – a 0.1-second improvement over the six-speed auto.

Its 29-mpg highway rating represents a 3.5-percent increase over the six-speed. New eight-speed models are EPA-rated at 16 mpg in the city and 20 mpg combined.

In fact, the Stingray's stingy fuel consumption on the highway is not only better than sports car competitors such as Porsche 911 Carrera (28 mpg), Audi R8 V-8 (20 mpg), Jaguar F-Type R (23 mpg) or Nissan GT-R (23 mpg), it tops conventional cars with smaller engines, like the Subaru Outback six-cylinder (27 mpg), Volkswagen Passat six-cylinder (28 mpg) and Mercedes-Benz C350 coupe (28 mpg).

The greater performance and efficiency enabled by the available, GM-developed Hydra-Matic 8L90 eight-speed automatic is due primarily to its 7.0 overall gear ratio spread, which enhances off-the-line performance with a more aggressive first gear ratio – 4.60 vs. 4.03 on the six-speed – helping achieve the quicker 0-60 time. It also delivers world-class shift times that rival the best dual-clutch design.

Combined with a new, numerically lower 2.41 rear axle ratio vs. the 2.56 gear used with previous six-speed automatic models, engine rpm is reduced by 8 percent (123 rpm) on the highway at 70 mph. The lower engine speed reduces fuel consumption. Z51-equipped models retain a 2.73 rear axle ratio.

The new paddle-shift eight-speed automatic complements the performance generated by the Corvette Stingray's LT1 engine – rated at 455 horsepower or 460 horses with the available performance exhaust system – which uses advanced technologies including direct injection, variable valve timing and Active Fuel Management (cylinder deactivation) to make more power with less fuel.

Advanced composite materials in the body structure and a lightweight aluminum frame, as well as aluminum and magnesium suspension components, support the Corvette's efficiency with a low curb weight of only 3,298 pounds /1,499 kg (Stingray coupe). They also enhance performance by giving the Stingray an excellent power-to-weight ratio of 7.25 – or one horsepower for every 7.25 pounds of mass. That's better than Porsche 911 Carrera's 8.7 ratio and Audi R8 V-8's 8.3 ratio.

For those who prefer a traditional manual-shifting driving experience, the 2015 Corvette Stingray is available with a seven-speed manual that delivers 0-60 times of 3.8 seconds and EPA-estimated 29 mpg on the highway.