SAE J2807
SAE J2807 is the industry test standard for tow ratings, covering acceleration, grade launch, cooling on the Davis Dam grade and handling with a defined trailer.
How this site uses it
Toyota adopted J2807 from 2011, Ford, GM and Ram from the 2015 model year, Honda and Nissan later. Pre-J2807 ratings for the same model can be higher and are not comparable. Each model year on the site carries a J2807 flag where the manufacturer states it.
Related: GCWR · Towing calculator