time2roll wrote:
With 4500 pound trailer no extra engine braking is needed. Even at the full tow rating no additional engine braking is needed. This would be what the truck is rated for.
https://fifthwheelst.com/SAE-J2807-Tow-Tests.html
The standardized tow rating tests don't involve anything with downhill braking, where your brakes might fade from overuse and cease to be effective. All they require is that the combination be able to stop in <80ft from 20mph without leaving the lane. Stating that equates to driving in the mountains is disingenuous at best.
Even with J2807, tow ratings are ambiguous and often unequivocal to real-world performance.
