General Motors has official announced its new 8L90E Hydra-Matic eight-speed automatic transmission will be available in the 2015 Chevrolet Silverado and GMC Sierra 1500 equipped with the 6.2-liter V8 from the 2015 model year onward. The new eight-speed was developed in-house and introduced in the 2015 Corvette Z06, but will also be used in several of the automaker’s other models.
The new transmission has 11 percent greater torque capacity than the outgoing 6L80 six-speed automatic trans which is currently in use in the company’s full-size trucks and SUVs. Thanks to creative packaging, the eight-speed has remained the exact same size as the six speed unit but surprisingly, is lighter than it. In truck applications, the transmission has a wider 7.0 overall gear ratio to help drivers start with confidence when towing a heavy trailer.
GM says the 2015 Silverado 1500 equipped with the 6.2-liter engine and eight-speed automatic transmission will have a maximum trailer rating of 12,000 pounds. EPA estimated fuel economy ratings will likely improve and are to be announced closer to the start of production in the fourth quarter of 2014.