SAE J2807 2022 2500 HD

dquest · February 25

All numbers are from door stickers on my 2022 2500 CC LB Gasser. My questions is around actually towing numbers. GVWR 10650, GAWR Rear 6390, max payload 3473 but max GN as per SAE J2807 is 2460. I'm looking at 5th wheels but it seems that my max GVWR is 11150 ( 22% for hitch weight is 2453 ).

I seem to have quite a bit of room for a hitch and gear. ( excluding full fuel and 300 lb for pass as part of curb weight )

Is the SAE rating based on RAWR max load to safely pass the tests? Wondering why it's almost 1k under max payload, assumption on avg gear etc being close to 1k? I'm not able to get an actual hitch weight sitting on a truck for the rv's I'm looking at.

AndrewF · February 25

A good summary. Essentially GM uses 15% for pin rating without regard for axle/spring capacity for GN trailers. Even though their own trailer guide says 15-25% is ok.

Chopper_Man · February 25

Right below the sticker you got those numbers from is another sticker with all your trailer weights. Don't forget to add 300#'s for the 5er hitch.

dquest · February 26

AndrewF, Thanks for the info. Seems like I'm stuck with a smaller trailer or get a bigger truck !!!!

Chopper_Man, I did get the 2460 number from that sticker ! I Must say it surprised me to see that number , good bye Mid Bunk 5er !!!

vucelick · February 26

I went thru the same tow math you went thru. I did not want a diesel or a dually, so i compromised and got a diesel dually. Because all of the toy haulers i was looking at are heavy pigs.

Edited February 26 by vucelick

dquest · February 26

I'm really trying to avoid that...... they are only 130k tho so you never know ....lol

vucelick · February 26

My 2025 LTZ 3500 diesel dually was just under 90k tax included.

Another JR · February 27

After reading much of the J2807 test method and discussing the various tests with a family friend who did those tests for RAM trucks for a couple of test programs, here is my understanding.

The limits that are driving that gooseneck (or 5th wheel) pin load limit are the gross combination weight rating, which limits the the trailer weight that corresponds to that GCWR, and the pin load weight percentage that GM selected to use for the J2807 testing. The GCWR is generally limited by either the acceleration test (simulating acceleration onto a highway) or the drivetrain temperature test in a specified hill climb. That and the minimum reasonable truck weight (I don’t know what defines that - full fuel plus driver?) limit the trailer weight.

The fairly light 15% pin load that goes with that maximum trailer weight is kept low in order to pass the turning and quick avoidance maneuver tests for the truck/trailer combination. If the weight on the pin is higher in those tests, more lateral tire scrubbing of the truck rear axle occurs, which causes an oversteer tendency. Excessive oversteer fails those tests.

So bottom line is the max pin load is driven by handling characteristics testing and how the manufacturer chose to configure the combination for the tests, but maximum truck payload is limited by rear axle/tire capacity RGAWR.

Edited February 27 by Another JR