TFLtruck recently received this question from Eddie C. Basically, can I tow two pickups on a flatbed gooseneck trailer with a 2015 GMC Sierra 3500 HD?
I just finished watching your towing test runs with the 2015 GMC Sierra 3500. I really like this truck. But, I am not sure if it’s capable of doing what I needed to do. I want to start a small 2 car transporting business and I have a 43ft gooseneck trailer with 2 axles. I want to know if this setup will get the job done with no problems. I posted some pictures so you can see what I am talking about. Please let me know if I am on the right track.
Eddie C.
What a great question! It illustrates the thought process behind choosing the right truck and trailer for the job at hand.
Tow Vehicle
First, lets get the specifications for the 2015 GMC Sierra 3500 HD Denali (with single-rear-wheels). This will determine if it is rated to do the job safely. This is a crew cab 3500 HD 4×4 truck with the 6.6-liter Duramax V8 turbo-diesel under the hood. Next, check the rear axle ratio. If it has the 3.73 rear axle, then it’s rated at 17,100 lbs of maximum towing via gooseneck. More importantly, the Sierra’s GVWR is 11,500 lbs. The GCWR for the truck is 24,500 lbs. It’s important not to exceed these two numbers, and also leave yourself some safety margin. See below for the trailer weight calculations.
Trailer and Load
The trailer in question is a 43-foot flat-bed with a gooseneck hitch. It’s long enough to carry two full-size crew cab pickup trucks. However, lets look at the capacity stickers.
The maximum cargo weight is said not to exceed 8,120 lbs.
A full-size crew-cab 4×4 pickup truck can easily tip the scales at over 5,400 lbs. Often, additional options put the curb weight over 5,600 lbs. Lets just say that two trucks weigh about 11,000 lbs for the sake of this example. This is obviously way above the maximum weight rating.
The GVWR of this trailer is 14,000 lbs. It has two axles. Basically, it is equipped with two 7,000 lbs axles, which is actually very common. The actual weight of the empty trailer is not specified, but it is likely near 5,880 lbs (14,000 – 8,120 lbs).
If you put two pickups on the trailer, then you are towing (5,880 + 11,000 = 16,880 lbs). This is just under the 17,100 lbs max towing rating on the Sierra 3500 HD. There is not a lot of safety margin, so a truck with a slightly higher rating may be required.
Now, the trailer pushes down on the truck with some amount of “tongue weight”. For a gooseneck trailer, this amount can vary depending on load distribution, but it could be around 20% of total trailer weight. In this case, 16,880 lbs * 0.20 = 3,376 lbs of tongue weight. This is well within the maximum payload rating of 4,264 lbs for this Sierra HD.
You can now argue that if you subtract the tongue weight from total trailer weight (16,880 – 3,376 = 13,504 lbs), then the two trailer axles are carrying under 14,000 lbs. Since, tongue weight can vary, there is no definitive way to say that this trailer is adequate for the job.
I recommend to either: get another trailer with GVWR of over 17,000 lbs or upgrade the axles on this trailer to 9,000 lbs each.
Eddie, thank you for submitting your question and providing all the images.
Watch how this exact truck – 2015 GMC Sierra 3500 HD Denali single-rear-wheel – handles the Ike Gauntlet extreme towing test.
And get the low-down on what it’s like to be an independent car hauler here.
