Originally Posted by greobr33
I disagree. Do you think that if a vehicle is rated for #2000 capacity that #2001 pounds will break it?
There are safety factors build into the capacity ratings on all vehicles. Look at the full size towing wars going on on paper. The capacity numbers are sky-rocketing. How can that be? The drive-trains haven't changed enough to warrant the number's increases. What is happening is the manufacturers are changing their safety factors. The standard used to be 2.4, it is probably more like 1.6 now. A 1/2 ton 2WD Chevy pick-up is rated to tow #12,000. Really?
You can work yourself into a 3/4 ton pick-up for a pop-up if you keep adding safety factors on top of safety factors. You don't put only 4 people into a 5 passenger vehicle because you are adding safety factors.
In the end, you have to do what you are comfortable with and road test it to assure you are. I have found people drive way too fast when towing and that causes many problems.
As an engineer I can appreciate the safety factor statement. I'm sure there are tons of safety factors built in. There has to be. As far as the 1/2 ton races I'm sure some of it is the margin of safety being reduced but some of it also has to do with other components besides drivetrain being strengthened to up the capacity. The GVWR has more to do with just the ability to pull the load. The suspension and braking as well as a whole host of components come into play. It's all about the weakest link and that may not be drivetrain.
You're also missing another component of this and that is the legality of exceeding the GVWR of your vehicle. While it is unlikely that during normal operation you may not have a problem but if you get into an accident it could be very bad. I know I've been cut off and then had the person in front of me slam on their brakes. If you get into an accident and it comes into light that your vehicle was over GVWR there could be a whole lot of trouble coming your way. Your insurance may not cover it. You could lose your license. Concentrating on the pure pulling capacity of the TV without knowing your safety factor exactly, for each component, is irresponsible. Regardless of how comfortable you are.
Your examples are also extremely misleading. No you don't put only 4 people in a 5 person car because that's what the car was designed for. If the Chevy 1/2 ton was designed for 12,000# then that's what it was designed for. I'm not an automotive engineer and I don't have the testing or the knowledge to make the call so I defer to the people who do. I'm not trying to add more safety factors, I'm trying to stay within the margin of safety stated by people with more knowledge and deeper pockets than me.