In this video we’re going to be demonstrating the testing involved that goes into declaring a vehicle’s tow rating. In other words, how are tow ratings determined? Well that question used to have a very subjective answer based on which truck company you were asking, but the major players in heavy duty trucking put together a standard, SAE J2807, which includes a series of tests that the trucks must pass at their rated load.
source/image(PrtSc): Engineering Explained
This demonstration is taking place at FCA’s Chelsea Proving Grounds in Michigan, and our demo vehicle is a RAM 3500 4×4 with the optional 6.7L Inline-Six Cummins Turbo diesel. 400 Horsepower and 1000 lb-ft of torque. It will be towing a trailer with ballast added, weighing 30,645 lbs, for a gross combined weight of the truck and trailer just under 40,000 lbs, targeting to max out the combined weight rating for the truck./read more: Engineering Explained
Was the the vehicle in this video at capacity? Yes, but it’s rather confusing how we get there. The combined truck + trailer weight in this video is 39,840 lbs (with no people). The combined weight rating is 43,000 lbs – which you’d reasonably assume we’re down 3,000 lbs.
However, the vehicle’s Gross Vehicle Weight Rating (just the weight of/on the truck) is 14,000 lbs, and we’re at 13,700 pounds (without driver, but with the tongue weight of the trailer) in this vehicle, so we’re hitting max GVW before hitting max GCW. Why? Because this is a Limited truck, not the base truck, which will have a lower curb weight with few features, smaller cab, 2WD, etc./via/read more: Engineering Explained