The 2024 GMC Sierra HD Denali Ultimate is all new. This special luxury trim of this 6.6L Duramax Diesel V8-powered truck did not exist before. Its turbo-diesel is now more powerful than before, but is it the “ultimate” towing machine? Mr. Truck and I find out by doing something very that’s never been done on the Ike GauntletTM before. We pull a big 5th-wheel camping trailer! Let’s find out how it does.
2024 GMC Sierra HD
This updated Sierra HD 2500 truck has a fresh style on the outside and a new interior inside. The 6.6L Duramax is now rated at 470 horsepower and 975 lb-ft of torque. The engine is mated to a 10-speed Alisson-branded transmission.
This beautiful ATC 3619 Game Changer Pro all-aluminum 5th-wheel toy hauler is 8.5 feet wide and 13.5 feet tall. These are the same dimensions as a semi-truck trailer. The length of this trailer is a bit less than that of a semi-trailer. This one is 37’3” long. This trailer’s empty weight with some options is 11,500 lbs. We loaded a Honda Pioneer 1000-5 Trail side-by-side to bring the total trailer weight to around 13,500 lbs.
This GMC Sierra HD 2500 has a payload rating of nearly 3,000 lbs and a 5th-wheel tow rating that is nearly 18,000 lbs. The ATC trailer enabled us to tow it with this 2500-series pickup truck because of its aluminum lightweight construction. We measured our trailer’s tongue weight at 2,600 lbs. We are pushing the maximum payload capacity of this truck.
The new engine updates made the downhill section easy and painless. The new and improved exhaust brake capability slowed us down nicely. We registered just one brake application.
On the way up, we saw an impressive 8 min 6 seconds climb with a truck-reported 3.6 MPG. A perfect time up the mountain is 8 minutes. This truck is also quiet and refined. The suspension is comfortable under load.
We give this truck a nearly perfect 4.75 out of 5 stars. The only downside was our overall fuel economy with this trailer. It was close to 8.0 MPG after about 165 miles.
Join the video below for all the fun.