Chevrolet Forum News

Filed under: Coupe, Performance, Chevrolet, Quick Spins



If the world were populated exclusively with Autoblog commenters, Chevrolet probably wouldn't even offer an automatic transmission in its 2015 Corvette Stingray. Somehow the desire to drive with three pedals and the willingness to leave your two cents on a digital car review are inexorably linked.

But, of course, the comment section of our fair website is not the real world, exactly. The reality is that some 65 percent of Corvette C7s sold so far have been equipped with two pedals. During the 2014 model year, that has meant that the almost universally lauded new Stingray has shipped mostly with a six-speed automatic that wasn't up to the technological standards of the rest of the car.

When he reviewed the C7 for the first time, our own Michael Harley had these, not-minced words to say about the existing 6AT:

"The traditional six-speed automatic seemed to extinguish the C7's performance edge. I found it softer, slower and more lethargic (even paddle-initiated shifts had annoying lag). Even though it was every bit as quick in terms of outright acceleration, the gearbox took much of the excitement out of the driving experience."

Clearly there was room to improve.

Thankfully, I can now report that the improvements have been made, and that the new, General Motors-designed Hydra-Matic 8L90 is up to the task of shifting one of the best sports cars in the world. Take heed, 65-percenters.

Driving Notes

• With some fantastic, many-geared automatic transmissions on the market from specialized companies like ZF, GM engineers knew that their unit would need to be world class. To that end, they concentrated on improving performance without sacrificing durability; all while needing to satisfy the challenging packaging requirements of the Corvette. Aluminum and magnesium have been used to reduce rotational mass, while pressed steel parts can still be found in the torque-bearing bits of the trans. A chain-driven, binary-vane oil pump in the sump has even been optimized for low- and high-speed engine loads. All of that helps to make this 8AT incredibly fast acting and responsive, while also improving fuel efficiency.
• And it's strong. The trans was designed around the upcoming Z06, meaning it had to be rated to handle more than 650 pound-feet of torque.
• Down to it then. Executing shifts in manual mode feels dual-clutch quick, for sure. The Chevy guys were puffing out their chests talking about the speed of this 8AT versus Porsche's PDK, and the truth is that the reaction time from paddle-pull to upshift is right there. At least, as that's what my imperfect human brain can suss out - any advantage to the quickest dual clutches I've yanked would require a machine to judge.
• For my money though, and for the love of the 65-percent, the real test comes when you leave the lever in D. I actually did all but one of my laps of GM's dizzying Milford Road Course in full auto mode, and found the programming and response time of the trans to be impeccable. Set to Race mode, the software seemed to have me in the right gear for every corner entrance and exit, holding each of the short ratios for maximum power delivery as I ran up the few straight bits.
• I got a hot lap with one of the GM hotshoes, as well, which confirmed outright capability of the 8L90. I may not have believed my driver's rhetoric alone - he told me he was quicker in full auto than when shifting for himself - but on his lightning lap, I could hear the car clicking off gears in synchronization with the needs of the track.
• As for driving on public streets - of which I did for perhaps 50 miles - the AT is just dandy, too. To be fair, it's over the course of spirited-back-road driving that the involvement of a manual transmission is most enjoyable to me. But the eight-speed had no issue going from leisurely cruising to the occasional moment of massive corner attack, and back again.
• For daily driving, Chevy says 8AT owners will see a 3.5-percent improvement in fuel economy. Preliminary EPA estimates show ratings of 29 miles per gallon on the highway, 16 in the city and 20 combined (with the standard engine). What's more, I was told those numbers should continue the Corvette tradition of being easy to achieve in the real world (something owners are strangely likely to brag about).
• Oh, and the new auto is quicker to 60 mph, too - 3.7 seconds to do the deed with the Z51 performance package. That's a tenth quicker than the manual, for the record.
• It is also just a bit more expensive. Though full pricing for the MY15 cars hasn't been given yet, I was told the eight speed will add $1,800 to the sticker price, versus the $1,600 asked for the outgoing automatic.
• There's no question that the great things we had to say about the 2014 Corvette stay true for 2015, too. The handling at a race pace is sublime with occasional moments of scariness if you, like me, don't go to work in head-to-toe Nomex. I was particularly impressed with the overall grip of the car, even after I did half a lap of MRC in some light rain. This is a balanced, poised machine until you get silly with it (and even then, it's still fun).
• On a personal note, and repping for the really tall guys everywhere, I will say that there's less room in the cabin for my six feet and five inches than I'd like, at least when I'm wearing a helmet. On public roads, I felt a bit cramped laterally, but not so badly that I'd feel the need to, you know, not drive a Corvette. On the other hand, if you're really tall and looking for a car to track, you might want to measure out carefully.

To sum: the 2015 Corvette Stingray is a brilliant sports car made better for most of its actual buyers with this transmission. It may not be the purist's special, but it is a highly advanced unit that will offer real gains for many drivers, and is closer than ever to the goodness of the enthusiast-darling stick shift. You may not love my saying it, Average Autoblog Commenter, but you really should respect these AT chops.2015 Chevrolet Corvette Stingray originally appeared on Autoblog on Wed, 20 Aug 2014 11:57:00 EST. Please see our terms for use of feeds.



Permalink | Email this | Comments

More...