The test vehicle and trailer must stay within a 11.5-foot wide traffic lane during stopping tests. The parking brake must be capable of holding the rig on 12-percent up and down grades.
Stopping distance requirements from an initial 20 mph without use of trailer brakes are:
- In 35 feet or less with a TWR of 3000 pounds or less and no trailer brake requirement.
- In 45 feet or less with a TWR of 3000 pounds or less and a trailer brake requirement.
- In 80 feet or less for TWRs above 3000 pounds.
To assure that the tow vehicle's structure is capable of towing a particular trailer load, standard J2807 specifies that no more than 5 degrees of permanent angular deformation at hitch attachment points is acceptable. Also, the highest experienced trailer hitch attachment force must be withstood for five seconds without significant loss of load (no structural deflection).
The SAE towing committee purposely defined the scope of this standard not to include brake fade and durability aspects related to the tow vehicle such as the endurance of chassis, powertrain, suspension, and brake components. Other SAE standards and each manufacturer's own internal requirements instead address these towing issues.
If all requirements specified in J2807 are met, the tow vehicle manufacturer may state the following: This model meets or exceeds the tow-vehicle trailering requirements of SAE International per SAE J2807. All manufacturers are strongly encouraged to use this test for tow ratings beginning with the 2013 model year. Some brands that have tired of the leap-frog game -- Toyota for one -- have already commenced use of this worthwhile trailer towing advancement.