2015 Chevrolet & GMC's models to offer 8-speed transmission
In an effort to maximize fuel efficiency and performance, both Chevrolet and GMC will offer 2015 models featuring a brand new eight-speed automatic transmission.
The new eight-speed (a Hydra-Matic 8L90, just in case you asked) will come standard on the 2015 Chevrolet Silverado, GMC Sierra, and GMC Yukon Denali/Yukon XL Denali models equipped with the 6.2L EcoTec3 V8. The transmission will help provide even more confidence in first gear when towing a trailer and will also reduce engine rpm on the highway, saving gas.
At 420hp and 460lb-ft of torque the 6.2L EcoTec3 is the most powerful engine offered in any light-duty pickup and offers a maximum available trailer rating of 12,000lbs. As with many other engines in the EcoTec3 family, the engine only uses four-cylinders under light loads–seamlessly deactivating the other four cylinders– to improve fuel efficiency.