The Hydra-Matic 8L90 and GMC Yukon Denali
It’s no secret that GM is constantly looking for new ways to improve the fuel economy of their vehicles from the Spark all the way up to the Yukon XL Denali.
While the Spark has the little engine to sip fuel, the Yukon Denali and XL Denali use the 6.2-liter EcoTec3 V8 to power it and it’s not exactly the most fuel sipping vehicle when you add 4WD to the mix.
In order to bring back some of those mpgs, the Yukon Denali model utilize the new, eight-speed Hydra-Matic 8L90.
Thanks to two more gears than the previous six-speed Hydra-Matic 6L90, the eight-speed is able to pull more ratios for better fuel economy along with the other various improvements in the EcoTec3 6.2-liter V8 engine.
While the 6L90 ratios were 4.027, 2.364, 1.532, 1.152, 0.852, and 0.667, the 8L90 utilizes ratios of 4.56, 2.97, 2.08, 1.69, 1.27, 1.00, 0.85, and 0.65.
With much longer overdrive ratios, a 3.23:1 differential ratio; the 420-horsepower, 460-lb-ft-torque 6.2-liter 4WD is able to pull 21 mpg on the highway while the 2WD is able to pull 22 mpg.
All of that and the Yukon Denali is able to tow up to 8400-pounds and the XL Denali up to 8100-pounds.
Here is a chart on how the Yukon Denali compares to its peers:
- 2015 GMC Yukon Denali – 6.2L EcoTec3 V-8 – 420 hp @ 5,600 rpm/460 lb-ft @ 4,100 rpm – 2WD:22 mpg/4WD:21 mpg
- 2015 Infiniti QX80 – 5.6L DOHC – V-8 – 400 hp @ 5,800 rpm/413 lb-ft @ 4,000 rpm – 2WD:20 mpg/4WD:20 mpg
- 2015 Lincoln Navigator – 3.5L twin-turbocharged V-6 – 380 hp @ 5,250 rpm/460 lb-ft @ 2,750 rpm – 2WD:22 mpg/4WD:20 mpg
- 2015 Toyota Sequoia Platinum – 5.7L DOHC – V-8 – 381 hp @ 5,600 rpm/401 lb-ft @ 3,600 rpm – 2WD:17 mpg/4WD:17 mpg
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