There are several reasons for the ratings:
1. Reliability (warranty)
2. Performance
3. Safety
4. Legal (registration)
#1 is what most people tend to ignore. Mainly because if you trade often, it will likely be the "next guy" that suffers the consequences.
Often the warranty will cover items that were caused by overloading...This may be coming to a end in the near future. With todays computers, it really won't be all that hard for them to be programed to "know" if overloading is taking place.
#2 is established by the manufacturers as a baseline of what they feel most customers will expect of their trucks. This is of course subjective, but soon when the SAE standards are fully in force, will not be... Look for legal standards to follow afterwards.
#3 is safety related items such as brakes. No one should be compromising in this area... Of course some safety items can also be considered in the other catagories as well.
#4 is the legal, which makes me groan every time it comes up. The laws vary all over the map, some with good logical reasoning behind them, and others with only money as the reasoning. Some have strict enforcement and teeth in the laws, and others are widely ignored.
To summarize. A TV is made up of many different parts that need to work together. The weak part will be the determining factor for what the rating is.. That is the reason why axle ratings are ALWAYS higher than GVW. Many axles are installed in different TVs... In trucks, it has not been unusual for the same basic axle to be installed in Fords, GMs, and Dodges.... Obviously they will not and SHOULD not all have the same ratings.
Whether one believes in the ratings or not will not be decided in this thread....
I do think that it is telling that the OP listed cost as his reason for NOT believing in them.
The truth is that their really isn't all that much cost difference among the Truck choices out there. One can easily move up a weight class for the price of forgoing leather seats etc.
