2015 GMC Sierra, Yukon Denali Fuel Economy Improves with Eight-Speed

Less than a year after debuting the 2015 GMC Yukon Denali, General Motors is already updating the model with a new eight-speed transmission that will replace the aging six-speed. As a result, fuel economy improves for both standard- and long-wheelbase Denali models. The 2015 GMC Sierra pickup truck also receives the new transmission, helping its economy ratings, too.

When paired with rear-wheel drive, the updated 2015 GMC Yukon Denali and Yukon Denali XL achieve 15/22 mpg city/highway, up 1 mpg from last year's highway rating. Four-wheel drive Yukon Denali models are rated at 15/21 mpg, an increase of 1 mpg in the city. There are no fuel economy improvements for the four-wheel-drive XL Denali, which continues to be rated at 14/20 mpg. The 2015 Cadillac Escalade is also earmarked for the same transmission upgrade sometime in the near future; its fuel economy ratings will likely match those of the Yukon Denali and Denali XL.

The 2015 GMC Sierra and 2015 Chevrolet Silverado also receive the eight-speed upgrade for 6.2-liter V-8 models previously saddled with a six-speed transmission. Fuel economy for these twinned pickups remains the same in rear-wheel-drive models (steady at 15/21/17 mpg city/highway/combined), but there's a slight uptick for four-wheel-drive models. Compared to 2014, the new 2015 GM pickups get an extra mpg in both city and highway categories, now totaling 15/21/17 mpg. The change means that now there is no longer an efficiency penalty for selecting four-wheel drive compared to two-wheel drive.

GM says its new transmission promises quicker shift times than before. A new torque converter should deliver smoother performance at low speeds, particularly when carrying heavy loads.

The 2015 GMC Yukon Denali's new fuel economy ratings are on par with the V-6-powered 2015 Lincoln Navigator, but exceed eight-cylinder models like the Toyota Sequoia Platinum and Infiniti QX80. Non-Denali Yukon models with the 5.3-liter V-8 and six-speed automatic achieve slightly better fuel economy at 16/23 mpg hwy with two-wheel drive, and 16/22 with four-wheel drive.

The Yukon Denali keeps its familiar 6.2-liter EcoTec3 V-8 engine that produces 420 hp and 460 lb-ft of torque. Towing remains at up to 8400 pounds for the Yukon Denali, and 8100 pounds for the Yukon XL Denali.

Equipment updates for the 2015 Yukon Denali and Yukon XL Denali include a new hands-free automatic liftgate, 4G LTE compatibility, Wi-Fi hotspot technology, a new text-message alert system, and a wireless cell phone charging mat integrated into the center console.

Prices for the 2015 Yukon Denali start at $64,965, while the XL Denali begins at $67,665.

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