As I suspected for a long time.......the towing rating system was a bunch of BS until now.............
SAE J2807: The new common standard for tow ratings
by Richard Russell
If you are into pickups, you've seen the ads or are aware of the bragging among manufacturers about tow ratings.
Ford, Dodge (Ram) and GM (Chevy and GMC) all claim their trucks are the biggest, the strongest the most capable, etc.
What you may not realize, is that you can't compare these numbers.
Until now, there has been no common ground or no agreed-upon common standard. Each manufacturer has designed and runs its own tests.
As a new truck is introduced, the ads boast of a best-in-class tow rating. Then a competitor comes out with a new truck with a new "Âbest-in-class"Â rating.
This game of leap-frog has gone on for decades. Getting these three competitors to agree on the terms for a common methodology to standardize and validate tow ratings has been like herding cats.
The Society of Automotive Engineers (SAE), the professional association that sets technical standards for the automotive industry has derived a common standard SAEÂ J2807.
It was worked out in consultation with all major vehicle manufacturers and all have agreed to abide by it starting with the 2015 model year.
SAE J2807 involves a precise method of testing. In order to claim a rating for the number of pounds the truck can tow, the manufacturers must subject it to acceleration, braking and other procedures.
There are literally dozens of tests involved, each with specific procedures. For example, in order to be certified to tow a given weight, the vehicle must be able to accelerate from rest to a certain speed in a given amount of distance.
The new standard spells out the precise procedure for arriving the two most important and until now misleading ratings: maximum gross combination weight (GCWR) for a vehicle and its trailer and the maximum permissible trailer weight rating (TWR).
The tow ratings take into account the five factors that determine a vehicle's towing performance: torque, cooling, durability, braking and handling.
The standards spell out the frontal area of the trailer, the hitch/tongue design and how the weight it is distributed on its axles.
Until now the companies were not including the driver, passenger or any other items in the weight total. The new standard requires the addition of a driver and passenger in the calculation.
It also requires the manufacturer to include the weight of any optional equipment so a heavily-optioned vehicle will have a lower rating than a bare-bones base model.
In order to claim a given rating, SAE J2807 requires (all ratings in English units):
ACCELERATION
Vehicles with single rear wheels to accelerate from rest to 30 miles per hour in 12 seconds or less.
Dual rear wheels in 14 seconds or less.
Dual rear wheels and a GVWR of more than 13,000 pounds in 16 seconds or less.
Accelerate from rest to 60 mph in 30, 35 and 40 seconds respectively.
Accelerate from 40-60 mph in 18, 21 and 24 seconds respectively.
LAUNCH ON GRADE
Vehicle must repeatedly move from rest for a distance of 16 feet on a 12 per cent grade five times in succession in both forward and reverse direction within five minutes.
CLIMBING HILLS
Vehicle must maintain a minimum cruising speed, ranging from 30-40 mph (depending on number of rear wheels and GVWR as per acceleration above) while climbing ÂDavis Damn grade, a notorious 12-mile stretch of highway between Arizona and Nevada. This grade varies from three to seven per cent, averaging five per cent.
During this test, conducted at a minimum ambient temperature of 100 degrees F, the A/C system must be running on the coldest setting without recirculation and at the highest fan speed. This test can be simulated on a chassis dynomomenter.
BRAKING
The vehicle must be capable of stopping within 35-80 feet or less (as per number of rear wheels and GVWR above) from 20 miles per hour without the use of trailer brakes while remaining within a standard 11.5-foot wide lane.
The parking brake must hold the combined vehicle and trailer on a 12 per cent grade up and down.
There are other tests specifying the degree of understeer and the amount of flex at the hitch attachment point.
Starting with the 2015 model year, all light truck manufacturers have agreed to utilize the new common standard SAE J2807.
http://thechronicleherald.ca/wheelsn...or-tow-ratings
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