GM sees writing on the wall, goes to 8-speed transmissions

General Motors has seen the writing on the wall and rather than lag behind Ford and Ram Truck, they are adopting eight-speed transmissions as standard in all GMC and Chevrolet pickup trucks for the 2015 model year. The fuel economy game is heating up in the pickup truck market and the race is on to see who can use what technology to get the most gains.

It started with Ram when they introduced the 2013 Ram 1500 with its eight-speed transmission and vastly improved fuel economy numbers. Now, Ram may be  moving towards 9-speed transmissions (which are appearing in Chrysler’s cars) to further those gains. Finally, the company put a 3.0-liter diesel engine into the Ram 1500 as the first full-sized, half-ton pickup to offer a diesel engine in the U.S. market.


Over at Ford, there’s no slouching going on either. They’ve famously introduced the 2015 F-150 as an all-aluminum beast with several EcoBoost and other options to take that lightweighting and add on engine efficiencies.

GM knows that their EcoTec engine won’t cut the mustard by itself, so more is needed. They’ve developed a Hydra-Matic 8L90 eight-speed transmission specifically for their half-ton truck line and will be offering it as standard in the 2015 GMC Sierra and Yukon as well as the Chevrolet Silverado.

The transmission has a 7.0 overall gear ratio spread with the added spread going to first gear to give better load handling. Further, the transmission’s build allows for lower rear-end ratios, which improves highway fuel economy by lowering engine RPM requirements to hold speed. Given the EPA’s test mix for a combined rating, this is critical.

The new eight-speed transmission can be mated to any of the engines offered in the light-duty trucks in GM’s lineup, including the class-leading 6.2-liter EcoTec3 V8. The transmission will hold that engine’s tow rating of a massive 12,000 pounds (SAE J2807).

2014 EcoTec3 6.2L V-8 AFM VVT DI (L86) for Chevrolet Silverado

For those unfamiliar with the EcoTec line, these engines feature cylinder deactivation to improve fuel economy when not under heavy loads.

GM has promised more technical details and EPA ratings for the new setups when they get closer to production later this year.

Aaron Turpen
An automotive enthusiast for most of his adult life, Aaron has worked in and around the industry in many ways. He is an accredited member of the Rocky Mountain Automotive Press (RMAP), the Midwest Automotive Media Association (MAMA), the Texas Auto Writers Association (TAWA), and freelances as a writer and journalist around the Web and in print. You can find his portfolio at