Originally Posted by mike.t
Lefty. How does one figure out while going down the road how much tire friction & wind/weight drag is occurring? Also if the TV seems to hit/max out on this stated limit first we have chosen the wrong TV for our TT. Good rule of thumb (which i have learned on this forum) stay with in 75% of capacities.
Just my thought.
Guess that, when I was referencing payload, I was more focused on 5th wheel towing then TT towing. In our case, the pin weight (& weight of the hitch) of our 5th wheel pushed us closer to the max TV payload (GVWR) much faster than the GVW (or GVWR) of the trailer pushed us towards the max towing capacity of the TV.
Don't think I know exactly how to measure wind drag...but there is a formula to figure it out based on the frontal area of the trailer and the speed of travel...plus head wind. And, again I'm certainly no expert on tire friction, but I'm sure it can be calculated using tire composition, contact surface area, road material and weight applied to both by the TT/5'er. I took the liberty of assuming the engineers designing the TV took that into consideration when they calculated towing capacity. I might be wrong...
Oh...and I wholeheartedly agree on leaving a margin of safety...but believe the amount is up to the person doing the towing.