[Bill]

Paul -

Thanks for your comments. The Goodyear website isn't nearly as helpful as it looks at first. There is a lot of ambiguity. For example:

Originally Posted by pbuck1

I looked back at the information given by Goodyear on their site. It states quite clearly 65mph and 1870lbs @ 50psi right there in the same row in the load table.

Yup, I see this quite clearly.

Furthermore, it then says that you can inflate the tire 10psi more than the stated pressure for the maximum rating in order to drive between 66mph and 75mph.

Yup, I see this quite clearly, too. I read it as saying that if you increase the pressure, you can drive faster with the same rated load. Your assumption (quite reasonable, I think) is that this means

you should be able to inflate to 60psi, drive at 65mph and so gain even more margin.

But later on in the same document, under "Effects of Higher Speeds", it says "Tire load-carrying capability decreases as speed increases." Nothing more - it doesn't quantify this at all. But it sounds like what the clerk was talking about.

What the load tables don't tell you is whether increasing the pressure beyond the "rated pressure", but maintaining the same speed, increases or decreases the load-carrying capacity. The load table needs one more line - what happens if you raise the pressure beyond "rated pressure"? If load capacity turns around and decreases beyond rated pressure, maybe you can't drive faster unless you also decrease the weight. My head is spinning!

I think it must be that the manufacturers just do not put the same care into trailer tires as they do into auto tires where there is more competition and more exposure to lawsuits.

You may very well be right, but it doesn't make me feel much better.

All this ambiguiuty is why I think TM needs to move away from the hairy edge of the ratings, and use a more capable tire.

Bill