Is J2807 worthless?

mileshuff wrote:

ShinerBock wrote:
These are the two main reasons why I say raise the speed requirement which in turn would lower the tow ratings to a more reasonable number most pickup truck owners would tow with these trucks. Plus since the J2807 doesn't have a long distance down hill braking test I wouldn't mind seeing some lower towing numbers on these vehicles.

The gradeability test is done on highway 68 in AZ climbing from 550ft to 3500ft in 11 miles. It's a decent highway to use for such testing. Very few 2500/3500 trucks towing 25Klb+ rigs can sustain 55mph up this grade. Especially when its 115F! Making the test 55mph minimum isn't real world. I want tests that are inline with what the typical person would be experiencing.

For one, I don't think an 250/2500 should be towing 25K and and barely think a 350/3500 should.

Fore two, I don't think you are understanding what I am saying or how the J2807 works. If any of those 2500/3500 trucks you named above cannot tow 25k then their tow rating will decrease to an amount they can safely tow up the Davis Dam at the set lowest speed limit. That is how it works. The only thing that raising the speed limit requirement would do is make it harder to perform the test therefore the tow ratings will be lowered to a more reasonable number.... nothing more.

Basically this is how it goes. They take a 3500 DRW truck. They strap 20k to the back of that truck and send it up the hill. That truck maintains a minimum of 60 mph of the run which is well above the 35 mph so they strap more weight onto it and send it up again. The second run they strap 25k to the truck and it does a minimum of 50 mph up the hill. Now, any sane person would say "That is enough weight for a 3500/3500 truck", but these are truck makes that want to say that their truck is "best in class" so they strap even more weight and send it up the hill. On this run they strap 30k to the back of the truck and the truck is barely able to maintain 35 mph so voila... you have your tow rating of 30k. Keep in mind that this J2807 does not test towing that 30k down that very same hill.

So..... What will raising the speed limit to 55 do? Take the very same 3500 DRW truck performing the very same test above on the first run and send it up the hill with 20k. Like above it is able to do a minimum of 60 mph so they will put more weight on it. This time since they were so close to the 55 mph minimum, they only put 23k on the second run. The second run with 23k the truck ran a minimum of 55 mph up the hill so voila... you have your tow rating of 23k.

Now which is more reasonable for this 350/3500 truck to be rated to tow...30k or 23k? Again, keep in mind that the truck will not be test going down the hill towing that weight. Funny thing is, most of these 350/3500 DRW trucks were rated at around 23k before J2807 came out.


Although, I would have to ask how many typical people tow 30k in their 350/3500 or how many people hear tow 12k in their 150/1500 trucks? That is what these trucks are J2807 rated for since the standard is so low at 40 mph for SRW and 35 mph for DRW.