
There is another kind of truck. They are the full-size truck-based SUVs, such as the 2015 Lincoln Navigator and the 2015 GMC Yukon XL Denali. These giant luxury vehicles can carry seven or eight people in comfort, but they are also meant to tow relatively heavy loads. They are not rated to tow or carry as much as the pickup truck counterparts, but the 8,600 lbs maximum towing rating on the Navigator and the 7,900 lbs limit on the Yukon XL allow you to bring a horse trailer or a good-sized boat with you.
However, you need be mindful of the maximum payload rating. For example, if you hitch up an 8,600 pound trailer to the Navigator, you will have 610 pounds of payload capacity left over. This is because the trailer needs to be setup to push on the truck with 10% of its weight (or 860 pounds in this case). The leftover 610 pounds does not leave much capacity for people or cargo. The Yukon XL is in a similar situation with 702 pounds of payload remaining if you max out the trailer. If you want to bring more than three people and tow around 8,000 lbs, then you need to look at the respective light-duty or even heavy-duty pickup trucks.
This Ike Gauntlet towing battle is between the big 6.2L V8 in the Yukon XL with 420 horsepower and 460 lb-ft of torque @ 4,100 rpm; and the 3.5L EcoBoost V6 that makes 380 horsepower and 460 lb-ft of torque @ 2,750 rpm. The twin-turbo V6 makes the same amount of torque as the V8, but delivers it earlier in the rev range.
The other interesting part of the test is that the Yukon Denali is equipped with GM’s new 8-speed automatic transmission. We saw some gear ratio issues with the 6-speed automatic in the 2015 Chevy Silverado 2500 HD. The ratio gap between 2nd and 3rd gears was too great. Does the 8-speed automatic solve this issue? Check out the Part 2 video below.
Altitude Power Loss
We are measuring calculated power loss on this and all Ike Gauntlet runs. We need three variables to get this accomplished: barometric pressure, ambient temperature, and relative humidity. We measure this with a portable weather station near the Eisenhower Tunnel (at the top of this test). This time the data was: 19.76 inHg of pressure, 28F temperature, and low relative humidity at around 25%. The result is a calculated 33% loss of power at the top elevation of the test relative to the standard provided by the SAE (Society of Automotive Engineers). This is applicable to the naturally aspirated engines.
How did they do? Watch the videos at the bottom and take a look at the data table below.
Fullsize SUV – Ike Gauntlet
2015 GMC Yukon XL | 2015 Lincoln Navigator | ||
Model | Denali 4×4 | 4×4 | |
As Tested $ | $77,925 | $73,895 | |
Engine | 6.2-liter V8 | 3.5-liter V6 | |
Transmission | 8-speed | 6-speed Auto | |
Power (hp / lb-ft) | 420 / 460 | 380 / 460 | |
Tow Rating | 7,900 lbs (3.23 axle) | 8,600 lbs (3.73 axle) | |
Payload Rating | 1,492 lbs | 1,470 lbs | |
Test Load (trailer + ppl) | 7,750 lbs | 7,750 lbs | |
Suspension Sag | 0 in | 1.5 in | |
Ambient Temp F | 28F | 28F | |
Relative Humidity | Low (25%) | Low (25%) | |
Barometric Pressure (at top) | 19.76 inHg | 19.76 inHg | |
Calculated Power Loss | 33 % | N/A | |
Down: Transmission Temp | normal | normal | |
Up: Time | 7:41.60 | 7:30.20 | |
Up: MPG | 4.1 | 3.6 | |
Up: Transmission Temp | normal | normal |
2015 Lincoln Navigator – Ike Gauntlet extreme towing test.
2015 GMC Yukon XL Denali – Ike Gauntlet extreme towing test.

Andre Smirnov is a life-long automotive enthusiast, writer, reporter, and software engineer. He has been writing and reporting at TFL since 2011.