And while it might not be as flashy a feature as air suspension or a lightweight skin, the Silverado and Sierra will get their own eight-speed automatic for 2015, a transmission that will be paired with the company's Ecotec3 6.2-liter V8. The new cogswapper will also find its way into the GMC Yukon Denali, but for now, there's no indication why the Cadillac Escalade, Suburban, Tahoe and standard Yukon are being left out.
According to GM, the new gearbox is about the same size and weight as the current Hydra-Matic 6L80 six-speed. By the time the new powertrain combination enters production late this year, the EPA will almost certainly have gotten around to certifying the vehicles' fuel efficiency. Until then, feel free to speculate. The current Silverado with the 6.2 and six-speed auto returns 14 miles per gallon in the city and 20 on the highway. How much do you think the eight-speed will improve those figures? Scroll down for the official press blast from General Motors, and then head into Comments.
DETROIT – Chevrolet and GMC have confirmed a new eight-speed automatic transmission will be standard on 2015 Chevrolet Silverado, GMC Sierra and GMC Yukon Denali/Yukon XL Denali models equipped with the 6.2L EcoTec3 V-8.
The GM-developed Hydra-Matic 8L90 eight-speed is approximately the same size and weight as the Hydra-Matic 6L80 six-speed automatic. Its 7.0 overall gear ratio spread is wider than GM's six-speed automatic transmissions, providing a numerically higher first gear ratio to help drivers start off more confidently with a heavy load or when trailering. The 8L90 also enables numerically lower rear axle ratios, which reduce engine rpm on the highway.
With 420 horsepower and 460 lb.-ft. of torque, the 6.2L EcoTec3 V-8 is the most powerful engine offered in any light-duty pickup, and offers a maximum available trailer rating of 12,000 pounds, based on SAE J2807 Recommended Practices. As with other EcoTec3 engines, it seamlessly switches to four-cylinder operation under lighter loads to improve fuel economy.
Additional technical details and the EPA estimated fuel economy will be announced closer to the start of production in the fourth quarter of 2014.