General Motors is confident its new 8L90 eight-speed transmission, which will debut in the 2015 Corvette Z06, will be the final piece of the puzzle that will edge the Corvette into an EPA-certified 30-mpg highway fuel efficiency rating, according to a report from the Society of Automotive Engineers.
“No comment—but we’re giving the vehicle team a ratio spread of seven that’s wider than the current 6-speed and will be useful in improving overall efficiency,” said Kavoos Kaveh, GM’s Powertrain Global Chief Engineer for 6 and 8-speed automatic transmissions.
Even though the 8L90 transmission was designed for use in the 2015 Z06, lead Corvette engineer Tadge Jucheter previously confirmed it will find its way into other applications eventually. Many assumed the standard Corvette Stingray would adopt the eight-speed transmission this year to coincide with the launch of the Z06, but Juechter has hinted more towards the standard car adopting the new unit for the 2016 model year.
“We’re very close to 30-mpg with the 6-speed car, so two extra ratios is something we like very much,” said Juechter.
GM says the eight-speed transmission improves the Corvette’s efficiency by up to 5 percent compared to the 6L80 six-speed currently in the Corvette Stingray. The unit is over 8lb lighter than the six-speed it replaces, while being equivalent in overall size. Engineers say it shifts 0.08 seconds quicker than the lightning-fast dual-clutch transmission in the Porsche 911 when under wide-open throttle, while a deeper first gear ratio improves launch capability.
Comments
Exceptional news. Excited to read reviews of it.
A brilliantly engineered trans to go with the brilliant engine, dif and chassis!
Now GM, this 8-speed should be destined for as many of your RWD base cars, trucks and SUVs in time for that 2015-16 model year. You need to adopt the similar strategy to BMW, Benz, Chrysler and other significant competitors.
Your strategy with Cadillac was poor. Why? Well, because the 2014 CTS line should have that interim 8-speed throughout, while the ATS should have been given the same treatment until this new 8-speed was available.
Hence, the ATS would have had better EPA numbers to gain equality with its competitors performance wise.
Therefore, all these new trucks, cars and SUVs badly need this 8-speed to regain some sort of advantage in the market place.
With the Silverado being so controversial with its generic front grill, we all know that GM needs to update these trucks ASAP,and this 8-speed across the truck and SUV line will regain much needed interest for their cash cow, along with a fresh looking front fascia at least for 2015. 2016 the latest
So, to those GM engineers and Managers, take my advice very seriously! Well, that is if you haven’t already started on this mission before this suggestion was even posted, I hope!
Doesn’t the 7 speed already get 30 mpg in Eco mode? Plus, if GM is really serious about fuel economy, they need to add e-assist across the line up especially in cars with a v8.