2015 GMC Sierra 3500 HD marks a thorough update to the GMC’s workhorse pickup line. This test vehicle is a single rear wheel setup Denali model with the good-old 6.6L turbocharged Duramax diesel V8. The engine specifications and the 6-speed Allison transmission remain the same. Duramax is the LML generation and rated at: 397 hp @3,000 rpm and 765 lb-ft @ 1,600 rpm.
GM did upgrade many aspects of the truck. There is a new design and styling on the outside and the inside. The HD trucks follow suit with the light duty truck, which GM redesigned for 2014. You get inlayed door design, and very comfortable and quiet interior. You also get new integrated engine braking feature, updated brakes, and chassis to handle even more load than before.
This particular 4×4 truck with the 6’6” bed is rated at maximum 4,262 lbs of payload and 17,100 lbs of towing. In case you are wondering, which configuration will give you maximum advertised payload and towing? You have to get the Sierra 3500, with: regular cab, dual rear wheels, 2WD, 8 foot bed, and the 6.0L gasoline V8. The 6.0L makes 360 hp @ 5,400 and 380 lb-ft @ 4,200 rpm. This will give you huge 7,374 lbs of payload, but it will not get you maximum towing. If you want 23,200 lbs of max towing, then you need: regular cab, dual rear wheels, 4WD, and the 6.6L Duramax. However, you could also get a crew cab, long bed, dually, with the Duramax and still have the maximum towing at 22,900 lbs.
We plan to hit the Ike Gauntlet with this truck, so please stay tuned.
Take a look at this insider TFLtruck video of the 2015 GMC Sierra HD debut from the 2013 Texas State Fair:
