Truck Manufacturers Agree To New Rating Standard

[HBarlow]

From RV Daily News Blog
Greg Gerber posted on July 12, 2011 11:58
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DETROIT -- Major makers of pickups and SUVs have agreed to a standard test to rate their vehicle's towing capacity, USA Today reported. By the end of the 2013 model year, most truck buyers should know -- for the first time -- how a vehicle performs vs. the competition.

"We wanted our customers to know that 10,000 pounds of towing capacity means the same things for all trucks," said Robert Krouse, the General Motors engineer who chaired the Society of Automotive Engineers committee that created the new standard.

Towing capacity measures how heavy a trailer a vehicle can safely haul. The SAE standard is a breakthrough, noted USA Today, because, until now, automakers could claim their own numbers for towing capacity.
Created with input from leading truck, trailer and hitch makers, the new standard assures that every truck tested fulfills the same performance requirements. It will allow apples-to-apples comparisons between trucks, the paper noted.

To read the full story in USA Today, click here.

 

[AH64ID]

Good deal. I beleive the max tow is rated to this standard!

Here is the meat and potatoes of the J2807 rating.

Acceleration Performance Requirements

The tow vehicle must meet these level road performance criteria to merit a particular TWR:

Acceleration from zero to 30 mph in 12. 0 seconds or less in vehicles with a single rear wheels.
Acceleration from zero to 30 mph in 14. 0 seconds or less in vehicles with dual rear wheels.
Acceleration from zero to 30 mph in 16. 0 seconds or less in vehicles with dual rear wheels and a GVWR over 13,000 pounds.
Acceleration from zero to 60 mph in 30. 0 seconds or less in vehicles with single rear wheels.
Acceleration from zero to 60 mph in 35. 0 seconds or less in vehicles with dual rear wheels.
Acceleration from zero to 60 mph in 40. 0 seconds or less in vehicles with dual rear wheels and a GVWR over 13,000 pounds.
Forty to 60 mph passing acceleration in 18. 0 seconds or less in vehicles with single rear wheels.
Forty to 60 mph passing acceleration in 21. 0 seconds or less in vehicles with dual rear wheels.
Forty to 60 mph passing acceleration in 24. 0 seconds or less in vehicles with dual rear wheels and a GVWR over 13,000 pounds.

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 directions. Five such launches must be accomplished within five minutes in each direction.

Highway Gradeability

To merit a particular TWR, a vehicle must be capable of maintaining a minimum cruising speed while climbing the grade at Davis Dam on state roads 68 and 163 in Arizona and Nevada. This 12-mile-long run originating in Bullhead City, Arizona, involves grades that vary between 3- and 7-percent with an average over 5-percent. During this test, the minimum acceptable ambient temperature is 100-degrees F. and AC systems must be operating on the maximum cold setting with no recirculation and the blower at the highest possible 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 pounds must maintain at least 30 mph.

To pass these hot-ambient-temperature, steep-grade challenges, 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 numerical axle ratio available from the manufacturer.

Handling Requirements

Standard J2807 specifies that an understeering handling attitude must be maintained up to at least 0. 4g cornering without a weight distributing hitch. With a weight distributing hitch (which transfers vertical load from the tow vehicle's rear wheels to its front wheels), an understeering attitude must be maintained up to only 0. 3g cornering.

Braking Requirements

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.