^^^ Impressive, very impressive work there

 

Yes very nice work! Thank you. The HDPP does help retain the tow capacity better than the MTT when adding payload to the truck. My point has been does Ford allow towing with more pin weight then the 15% of max tow rating (1725lbs in this case) even if overall total trailer weight is the same or lower. If so why isn’t the fifth wheel SAE tow rating higher? I’ve made 2 calls now to Ford customer service both say no, the 1725 is the max.

 

I assumed the tow rating was the same because either the brakes or chassis were not enough to handle more GCWR, not because of a numerical limitation. Why is it that you must have 20" wheels to get the new 2018 tow rating while the 17 and 18" wheeled trucks didnt change? I assumed it was because they had a lower profile, less floppy tire that possibly handled better. Ford figured out if they got specific enough and tested an extremely specific configuration they could jack up their claims again.

 

Also the rating for the engine and drivetrain to be able to pull it without overheating or putting too much stress on it.


You're right about the 20" wheel. Less sidewall. The wheel takes more of the weight compared to the rubber, as well as less flexing. Also why you don't want to tow heavy with big knobby mudder tires.

 

So can you not get the Max Tow and the HDPP packages together anymore? My '13 has both packages and wouldn't get it any other way for towing. If the new trucks can't get both packages that would be a game changer for me on my next truck.

 

You can, but per the owners manual there is what they call the heavy duty towing package now as well which I believe is above and beyond the regular max-tow package. Its not an option you can select in the build & price, it seems to just be automatically added when you choose a specific set of other option in a addition to max-tow(20" wheels, supercrew, and possibly some others).

So max tow is still available with HDPP, but because you cannot get 20" wheels it just gives you the same tow ratings as the 2017, not the increased 2018 tow ratings. This limitation applies to any truck that doesnt have 20" wheels though, not just HDPP.

 

Less sidewall is not good for towing. The more rubber the better the ride as you have more cushioning. Hit a bump with a 20" or larger wheel while heavily loaded and you might just bend the rim.
Finally with a 20" wheel the wheel doesn't take more weight than the rubber. The rubber has the entire weight no matter the size.

 

We're talking a 55 profile, not 20's. I think I'd have to hit a curb head-on at highway speed to bend my rim... Alberta secondary highways are horrible for bumps, holes, and railway crossings, and I've never had an issue. Less profile also means less side wobble, which is good for towing. My last vehicle had very large sidewalls, 33's on 16" rims, and the rear end wobbles sideways. Either way, on the towing and payload grids, there are notes showing that the higher weights require the 20" rims.

 

Even if all of this were true, I dont think J2807 includes pothole testing so it has zero weight when determining GCWR. It does test handling and braking which I am assuming a lower profile tire will perform better at since there is less flex.

 

I went from the stock 275/55R20 to a 275/60R20 and that was enough to make the truck feel less responsive. I ended up inflating the 275/60's to 40 psi to get the response back.

My Jeep liberty went from a 225/75R16(29.3") to a 265/70R16(30.6") and that made a huge difference in handling.