2015 Chevrolet Silverado, GMC Sierra Gain 8-Speed Auto

By | July 18, 2014
General Motors announced many of its 2015 pickups will receive a standard eight-speed automatic transmission that is also coming to new Corvettes. The new transmission will appear on 2015 Chevrolet Silverado, GMC Sierra, GMC Yukon Denali, and GMC Yukon XL Denali models equipped with 6.2-liter EcoTec V-8 engines. Currently, these models all have a six-speed automatic. Surprisingly, both the new and old transmissions share approximately the same size and weight, but the key differences lie in other areas. According to GM, the wider gear ratio spread in the new eight-speed will help drivers start off more confidently when carrying heavy loads. The new transmission also should reduce engine rpm on the highway. These GM trucks will continue to deliver 420 horsepower and 460 lb-ft of torque, and will offer a maximum trailer rating of 12,000 pounds.
We also strongly suspect that the new eight-speed will provide GM's trucks with better fuel economy over the previous model year. This seems to be the case for the new 2015 Corvette, which GM previously said will increase fuel economy by up to 5 percent thanks to its new transmission. More information is expected to arrive later this year, so stay tuned. Source: General Motors