OREANDA-NEWS. Thanks to the addition of an all-new 8-speed automatic transmission, the updated 2015 GMC Yukon Denali and Yukon XL Denali models now lead several competitors in horsepower, torque and highway fuel economy ratings.

Both the Yukon Denali and Yukon XL Denali now pair their 6.2-liter EcoTec3 V-8 engines with a new Hydra-Matic 8L90 eight-speed automatic transmission, designed to be more fuel-efficient than the Denali's previous six-speed automatic. EPA highway mileage estimates for two-wheel drive Yukon Denali and Yukon XL Denali models increase to 22 mpg with the eight-speed automatic, while the EPA city mileage estimate for the four-wheel drive Yukon Denali model rises to 15 mpg.

Within its segment, the Yukon Denali continues to deliver unrivaled power and efficiency. Denali's 6.2L EcoTec3 V8 delivers a segment-leading 420 hp and segment-leading 460 lb-ft of torque with highway fuel economy equal to or better than many 6- or 8-cylinder engines in competitive makes.

Compared to the Yukon Denali's previous six-speed transmission, the new 8L90 transmission offers smaller steps between gears, allowing the engine to efficiently leverage its peak power bands. The wider gearing spread also allows the use of a lower 3.23:1 rear axle ratio, which reduces engine speeds and fuel consumption, especially during highway cruising.

Comfort and capability are not compromised for fuel economy. Not only is the 8L90 transmission capable of handling more torque than the six-speed transmission it replaces, but its shift controls and solenoids are more responsive and provide quicker shift times. A new torque converter also delivers smoother performance at low speeds, especially when carrying heavy loads or pulling trailers. Tow ratings - up to 8,400 pounds for the Yukon Denali and 8,100 pounds for the Yukon XL Denali - are unaffected by the addition of the eight-speed transmission.

The 2015 Yukon Denali and Yukon XL Denali continue to blend unique design elements with upscale amenities, including premium interior materials. Convenience and connectivity improvements include:

A new hands-free power liftgate, which can be opened and closed by simply passing a foot beneath the rear bumper

A wireless charging surface for WPC (Qi) or PMA (Powermat) compatible mobile devices integrated into the design of the center console lid. A list of compatible devices is located at gmtotalconnect.com

OnStar with 4G LTE, which provides in-car data connectivity and a Wi-Fi hotspot capable of connecting up to seven devices at one time

An enhanced GMC Intellilink system, which provides incoming 'Text Message Alerts' when paired to a compatible Bluetooth phone

Owners of 2015 Yukon and Yukon XL models can receive a tutorial on these new features through a new Yukon-specific application for tablet devices, which supplements the owner's manual. The new Yukon app will be available for both Apple iOS and Android devices.

The updated 2015 Yukon Denali and Yukon XL Denali models are priced from USD 64,965 and USD 67,665 respectively, and are now available at dealers.