J2807 Requirements Summary

[dbj216]

I haven't read all 28 pages of this SAE test spec, but here is a summary I came across recently. I thought it reflected real world towing extremes. i think we consumers ought to press the manufacturers to adapt and post J2807 towing capacities on their vehicles.

Highway Gradeability - Davis Dam SR-28 at 100F, 40mph with no issues
Launch on 12% grade - forward and reverse
Level Road Acceleration - 0 - 60mph is 30 sec or less.
Tow Vehicle Understeer at .4g lateral acceleration
Trailer sway response - damping ratio at 60mph
Combination braking - stability, stopping distance at 20 mph, hold on grade

I didn't see any durability or reliability tests. But these data certainly demonstrates the vehicle is capable of towing the stated weight by the manufacturer.

It would help answer "will this tow that?".

David

[rostam]

SAE J2807 is great. The test is relatively comprehensive and allows for comparison of tow ratings for different vehicles by different manufacturers. From what I read, besides the tests you wrote about, there is also a test on the structural performance for the vehicle and hitch receiver. Toyota has been J2807 compliment for years. The big three, apparently, are compliant with their 2015 models.

[BoldAdventure]

I don't get why so many act like deceptive marketing is going to go away just because they're adapting a standard.

I already pointed out in another thread with a screenshot of Fords website, showing a truck with a lower tow capacity while mentioning a larger tow capacity with an asterisk.

You know why people get confused, isn't because there wasn't a standard. It's because the big 3 advertise the best rating, like it applies to all the configurations, when everyone here knows it doesn't.

You know, unless they are going to start printing a SAQ J2807 rating on the window sticker for each vehicle, this is still big whoopie doo.

[BoldAdventure]

Still up to their tricks. People will still continue to get onto forums after buying a truck believing it to be more capable and discovering things like, not having enough payload.

At least Ford used UP TO, Dodge buried that statement.

[rodsterinfl]

During the interview with Ford regarding the 2015 model F150, they confirmed that they were using the SAE J2807 standard. Toyota was mentioned as having already done this. The idea us a good one as then people can finally compare across brands for tow/payload capacity knowing that they are standardized. I believe that Chevy and Dodge will now comply.

[n2916s]

The new 2016 Nissan Titan is on board as well.

Mike

[rostam]

Originally Posted by BoldAdventure

I don't get why so many act like deceptive marketing is going to go away just because they're adapting a standard.

I already pointed out in another thread with a screenshot of Fords website, showing a truck with a lower tow capacity while mentioning a larger tow capacity with an asterisk.

You know why people get confused, isn't because there wasn't a standard. It's because the big 3 advertise the best rating, like it applies to all the configurations, when everyone here knows it doesn't.

You know, unless they are going to start printing a SAQ J2807 rating on the window sticker for each vehicle, this is still big whoopie doo.

But this is a different problem. Car manufacturers (like other businesses), BS to sell. Credit card companies, insurance companies, banks, etc are all deceiving the customers. This requires a separate/different solution.

[slowmover]

J2807 is notable primarily for what it ignores. It is not a guide to what a given vehicle can do. It may make for more realistic ad claims among trucks, but that is about it.

[rostam]

Can you be more specific about what J2807 ignores? My observation has been that folks like to thrash J2807 here as it does not help "their" argument.

[ROBERTSUNRUS]

Originally Posted by BoldAdventure

Still up to their tricks. People will still continue to get onto forums after buying a truck believing it to be more capable and discovering things like, not having enough payload.

At least Ford used UP TO, Dodge buried that statement.

Hi, I also noticed the new Dodge 1500 advertisement on TV; It's claiming the best fuel mileage and a huge tow rating. But it doesn't tell you that that's two different vehicles. It makes people think that one vehicle does both.

[jcl]

Originally Posted by dbj216

I haven't read all 28 pages of this SAE test spec, but here is a summary I came across recently. I thought it reflected real world towing extremes. i think we consumers ought to press the manufacturers to adapt and post J2807 towing capacities on their vehicles.

Highway Gradeability - Davis Dam SR-28 at 100F, 40mph with no issues
Launch on 12% grade - forward and reverse
Level Road Acceleration - 0 - 60mph is 30 sec or less.
Tow Vehicle Understeer at .4g lateral acceleration
Trailer sway response - damping ratio at 60mph
Combination braking - stability, stopping distance at 20 mph, hold on grade

I didn't see any durability or reliability tests. But these data certainly demonstrates the vehicle is capable of towing the stated weight by the manufacturer.

It would help answer "will this tow that?".

David

I don't think the SAE standard will help answer the "will this tow that" question. It will provide a basis of comparison between two different vehicles, but it doesn't feel like the real world in terms of capabilities.

Note, there have been several revisions, and my version may not be the latest.

IMO, if it was to be made more "real world" it would include:

• stopping from more than 20 mph
• stopping on a hill, and then more than one time
• the use of trailer brakes
• the use of sway control devices with hitches
• the use of 3P hitches
• some payload other than driver and passenger
• durability (if it is worn out after six starts on a hill, that is a pass)
• a limitation that if the hitch was permanently deformed you have too much tongue weight
• and so on

Those are difficult things to include in a standard, given the number of combinations. So in practice, I think they did fine with what they could cover. It just isn't a realistic towing limitation statement. If it was, someone could take the SAE standard towing capability figure, set up their truck that way, and head off camping believing all was well. We would then collectively chime in with "but you need trailer brakes, and make sure you can stop, and ensure your trailer brakes function, and use a sway control device with a larger trailer, and remember your payload limitation, ........"

It is like the SAE hp standard. We can easily compare the hp specs of two trucks if both manufacturers use it, since they are using the same size horses measured the same way, and that is great. But there is nothing in that spec that says how many horses are appropriate, or how a vehicle should be used to be safe, reliable, durable, etc.

Jeff

[Msmoto]

Maybe someone on the Air Forums can actually test a vehicle. In real world conditions, finding a 12% grade, doing some real 0-60 tests, braking distances, etc. The difficult and potentially dangerous test is in obstacle avoidance where over cooking into the incident might end in disaster.

I tend to be in the camp of those who believe the deceptions practiced by the advertising industry in most venues will hide the facts so well one can rarely find the truth. There is a driving force called profit motive which seems to override the idea that to be truthful is a good thing.

This who sell vehicles tend to make decisions which are not intended to make things easier, but instead more of a chore for the buyer. The solution for me is to tow with a large margin of error, i.e., having at a minimum 20% more than necessary so as to have a margin of error, and in situations such as mountainous regions, being able to get up and down the hills and not feel I am straining anything. My experience has been across the Rocky Mountains, and in backroads where 10% is occasionally found.

My 2008 Dodge/Cummins 6.7 l seems to provide this level of comfort well.

[BoldAdventure]

Everyone here is more than aware that when it comes to your tow rig, the options you chose effect what it is capable of. Toyota seems to have the least options, but the big 3 have the most engine/transmission/gear ratio options.

Since most consumers go to a car lot and buy a vehicle off the lot rather than ordering, it's incredibly easy for someone to go in thinking they are getting best in class towing, when in reality they bought the truck with the wrong gear/engine combo.

So I stand by my statement, that the standard is nice, but unless it's printed on each Vehicles windshield sticker so you can see what your truck is actually rated at, it's useless.

It just gives you an estimate.

But I think it's safe to assume that most 3/4 tons can get the job done. I think the tests really apply more so to the 1/2 ton market where it's way more competitive and the number of uneducated consumers is greatest.

I'll get off my soapbox on this issue now.

[rostam]

The standard tests the pulling/stopping/handling/cooling and is as real world as it gets.

I have noticed that the critics of J2807 on this forum are the same folks that state sedans/minivans are intentionally underrated by manufacturers. Without having a standard, you guys had a point, as you could claim tow rating was set arbitrarily. With a standard in place, you now have to show the sedans/minivans pass the tests (and I will bet you none of them will. Just read the description of Davis Dam grade test). So the best solution is to attack the standard. sigh.

[CDONA]

I don't know where SR 28 is, but SR 68 is the road between Bullhead City/Laughlin and SR 93 Hoover Dam/Kingman. Davis Dam/Lake Mohave is at the bottom on the Colorado river off on a side road in the Lake Mead Rec area, all 45 mph. The video that I saw had the "test" start within 3 miles of the 55 mph zone increasing to 65 mph leaving Bullhead City heading east.
The "Davis Dam SR 28" has to be some sort of a smoke screen, no locals call it that.

[Glenritas]

Originally Posted by CDONA

I don't know where SR 28 is, but SR 68 is the road between Bullhead City/Laughlin and SR 93 Hoover Dam/Kingman. Davis Dam/Lake Mohave is at the bottom on the Colorado river off on a side road in the Lake Mead Rec area, all 45 mph. The video that I saw had the "test" start within 3 miles of the 55 mph zone increasing to 65 mph leaving Bullhead City heading east.
The "Davis Dam SR 28" has to be some sort of a smoke screen, no locals call it that.

The real question is, in what state is SR 28 the J2807 referring to. After all we have 50 states and how many of them have a SR 28. I believe that is noted in in the J2807 specs.

If nothing else the J2807 gives specs that need to be meet to get the nod.

This would mean that say a 2015 F150 with a 4 cylinder turbo automatic and 3.50 gears would have to perform to that or it wouldn't meet the spec.

If it did how long do you think it would last ? But durability is not what the J2807 is about.

J2807 is about starting ,stopping, turning and braking. It also takes away the arbitrary one up's the manufactures were doing the last few years. Although the ad guys are still messing with the details in their ads.

Bottom line is 'Buyer do your home work.' other wise you may be sold this combo ...

[jcl]

Originally Posted by rostam

The standard tests the pulling/stopping/handling/cooling and is as real world as it gets.

I have noticed that the critics of J2807 on this forum are the same folks that state sedans/minivans are intentionally underrated by manufacturers. Without having a standard, you guys had a point, as you could claim tow rating was set arbitrarily. With a standard in place, you now have to show the sedans/minivans pass the tests (and I will bet you none of them will. Just read the description of Davis Dam grade test). So the best solution is to attack the standard. sigh.

As noted, the standard has several real world limitations. Stopping from more than 20 mph, stopping on a downhill grade, using trailer brakes, and so on. Things that are done in the real world, but not in the standard. So it doesn't seem like the real world to me.

If you want to revisit the car-as-a-suitable-tow-vehicle issue, there is nothing in the standard that says the maximum tow rating must be published. If a manufacturer has two similar vehicles (same engine, cooling, transmission, brakes, etc) but on different models, they can certainly decide to test and thus rate one at 6000 lbs towing (for example) and one at 3500 lbs towing. That would allow them to steer some customers to the more profitable vehicle, for example. What they couldn't do is rate the 6000 lb vehicle at 8000 lbs, arbitrarily (again, just an example)

If one wants to purchase a car to tow with, I guess they could go and tow a trailer up the Davis Dam road, do some acceleration and brake tests with the trailer brakes disabled, make sure their hitch doesn't permanently bend more than 5 degrees, and they would be most of the way there. The yaw sensors may be a touch more difficult to replicate, but most would tow with sway control in any case, something the standard doesn't allow.

A European tow vehicle I owned in 2003 did not meet any SAE towing standard. But that manufacturer tested to an internal test, that used a 12% grade, a figure they published. I found that interesting.

I am not attacking the standard. I was a member of SAE for years, and used a lot of the standards for everything from design work to witness tests. I just recognize the limitations of the standard. You can sigh again now

Jeff

[jcl]

Originally Posted by CDONA

I don't know where SR 28 is, but SR 68 is the road between Bullhead City/Laughlin and SR 93 Hoover Dam/Kingman. Davis Dam/Lake Mohave is at the bottom on the Colorado river off on a side road in the Lake Mead Rec area, all 45 mph. The video that I saw had the "test" start within 3 miles of the 55 mph zone increasing to 65 mph leaving Bullhead City heading east.
The "Davis Dam SR 28" has to be some sort of a smoke screen, no locals call it that.

The original poster got the road wrong. Here is the description from the standard:

Highway Grade ability Test is accomplished by running Arizona SR 68 (Davis Dam Grade) or simulated dynamic grade in a climatic wind tunnel. The Davis Dam grade is between Bullhead City, Arizona and Golden Valley, Arizona headed east on the east side of the Colorado River. The grade test begins at the intersection of Arizona SR 68 and McCormick Blvd. The posted speed limit changes from 45 mph to 55 mph, and then 65 mph. The test ends at the top of the grade (Union Pass), approximately 18.3 km (11.4 miles) beyond McCormick Blvd.

Note that manufacturers don't actually have to go run that grade. They can do this on a dyno in a wind tunnel as long as they can replicate the temperature. And the test is only at 40 mph anyway (for SRW; for DRW it is at 35 mph). The average grade is around 5%.

For the start on grade test (12%) they similarly don't have to find a 12% grade. It is permitted to use a lesser grade and adjust the figure mathematically for the difference.

Jeff

[dbj216]

Thanks jcl for your analysis of the standard. Yep, I got the highway number wrong. Sorry, I was working from memory, always a mistake in my case!

This SAE test standard does add significant meaning to the towing capability of a particular vehicle and drive train. Maybe we have seen our temp gages climb toward hot, or felt the transmission slipping due to heat, or panic when the brake pedal is no longer slowing the vehicle and trailer like it should. And all of this happening with a rather sharp curve at the bottom of the hill.

Towing a heavy conventional trailer significantly changes the vehicle dynamics. This standard will help us keep tow vehicles and trailers in better proportions.

David

[BoldAdventure]

Seems like the big 3 are only using it for 1/2 tons right now too.