I approach this subject with a sense of levity.
Ratings, capacities, weight
limits etc can easily be found officially within the folds of owner's manuals, yet many hours are whiled away reiterating or quoting them here.
Many of those same folks say that the manufacturer is the ultimate authority and should be followed to the letter, then immediately suggest that their numbers can not be trusted.
Well here is another facetious thread which I insist "must" be taken seriously.
Tow ratings, tongue ratings, axle
ratings, cargo capacity, tire age, frame fatigue, engine wear, transmission wear, even cooling system age can effect performance, capacity and safety.
Here are a few more completely arbitrary suggestions which must be considered in addition to all the other arbitrary or reasonable replacement or maintenance schedules.
For every year of service (or 10,000miles) you must reduce your vehicle's tow capacity by a minimum of 500 pounds.
Also you must reduce payload based on the same criteria by 100 pounds.
You must also weigh each person dressed for travel, add them all up and divide by 150, This will reveal your real world passenger number.
You must reduce your trailer axle
rating by exactly 5% per year.
You must reduce your towing speed by 5MPH per year of trailer age.
I assure you that each of these proposals can be supported by convincing arguments, both legitimate and otherwise. In the event of the failure of those methods, obfuscation may be substituted.
Any other suggested arbitrary or facetious rules can be added here and will not be considered hijacking.
Let the fun begin...