I hope this is not too much detail, but some out there may want to read this stuff…..zzzzzz
First, be aware that to get an actual copy of an SAE standard, requires purchasing the document from the SAE, Society of Automotive Engineers. We're talking maybe $200 or more. The info below is what I found in a publicly available document, and gives the highlights only.
Five key areas are addressed by the SAE J-2807 standard
1. An engine’s power and torque characteristics
2. The powertrain’s cooling capacity
3. Chassis and powertrain durability
4. Handling during cornering and braking maneuvers
5. The vehicle’s hitch structure
The tow vehicle must meet this level of road performance while towing to claim a particular Tow Rating
Acceleration from zero to 30 mph;
1. in 12 seconds or less in a vehicle with single rear wheels
2. in 14 seconds or less in vehicles with dual rear wheels
3. in 16 seconds or less in vehicles with dual rear wheels and a GVWR over 13,000 lbs
Acceleration from zero to 60 mph;
1. in 30 seconds or less in vehicles with single rear wheels
2. in 35 seconds or less in vehicles with dual rear wheels
3. in 40 seconds or less in vehicles with dual rear wheels and a GVWR over 13,000 lbs
Forty to 60 mph passing acceleration;
1. in 18 seconds or less in vehicles with single rear wheels
2. in 21 seconds or less in vehicles with dual rear wheels
3. in 24 seconds or less in vehicles with dual rear wheels and a GVWR over 13,000 lbs
Grade Launch Requirements
The tow vehicle must be capable of repeatedly moving from rest for a distance of 16 feet on a 12 percent grade in both forward and reverse. Five such launches must be accomplished within 5 minutes in each direction.
Highway Grade Ability
To achieve a particular rating, a vehicle must maintain a minimum cruising speed while climbing the grade at Davis Dam on State Roads 68 and 163 in Arizona and Nevada. This 12 mile run originating in Bullhead City, Arizona, involves grades that vary from 3 to 7 percent with an average of more than 5 percent. During this test, the minimum acceptable ambient temperature is 100 degrees F. The AC system must be operating on the maximum cold setting with no recirculation, and the blower on the highest setting.
Single rear-wheel vehicles must be able to maintain an average of at least 40 mph on this grade. Dual rear-wheel vehicles are required to maintain 35 mph or more here. Dual rear-wheel vehicles with a GVWR over 13,000 lbs must maintain at least 30 mph.
To pass this test, there can be no vehicle component failures, no warning lamps, and no diagnostic codes alerting the driver. In addition, the tow vehicle cannot lose any engine coolant. The vehicle under test must be equipped with the lowest axle ratio available from the manufacturer.
The new standard specifies that an under-steering attitude must be maintained up to at least 0.4g cornering without a weight distributing hitch. With a weight distributing hitch, and under-steering attitude must be maintained up to only 0.3g cornering.
The test vehicle and trailer must stay within an 11.5 foot wide traffic lane during stopping tests. Stopping requirements from 20 mph without use of trailer brakes are;
1. in 35 feet or less with a tow rating of 3,000 lbs or less and no trailer brake requirement
2. in 45 feet or less with a tow rating of 3,000 lbs or less and a requirement for trailer brakes
3. in 80 feet or less for tow ratings above 3,000 lbs
The parking brake must be capable of holding the rig on 12 percent up and down grades
To assure the tow vehicle’s structure is capable of towing a particular trailer load, J2807 specifies that no more than 5 degrees of permanent angular deformation at the hitch attachment points is acceptable. Also, the highest trailer hitch attachment force experienced must be withstood for 5 seconds without significant loss deflection.
Finally, the SAE towing committee didn’t include items such as brake fade and/or durability issues in its standards, as these are already dealt with in other standards and each manufacturers own requirements.
My comment; It also doesn't seem to include lateral stability at highway speeds. But, since this info which I found is only an overview, maybe it's covered elsewhere?