Originally Posted by nrkmann
The manufacturers ratings are such that they will not be sued.
Actually, they are so YOU don't get sued.
Engineers spend a LOT of time coming up with these formulas and now there are actual criteria and tests to rate towing capacity amongst manufacturers. In most cases, it's not the motor, the tranny, or the frame that cannot handle it; its the brakes and tires. Just because you can PULL 175% or even 200% over the rating, there is no rational reason you should be doing it.
The vehicle reaction times will be slower and the ability to stop will be slower and longer. And if you need to make an emergency maneuver, there is a significant increase in instability that can lead to jackknifing, etc. Doesn't matter if the trailer has its own brakes. When the tow vehicle is influencing the trailer's direction of travel, it needs to be the BOSS...periiod. The tail is going to be wagging the dog. When you are pulling, you are the boss, When she's pushing, you hope you have enough airbags. Things happen out there and you only need to be doing 25 mph and you don't have enough tow vehicle to prevent killing someone or ending up turned over in a ditch.
I'm not trying to preach, but being an engineer for a living, it's shocking how much I see of people exceeding design limitations with no data to back it up. Applying physics to engineering doctrine is not as simple as driving a couple of miles and saying "Yeah, this will work". Engineers don't do it this way and truck owners should not be doing it either.