</font><font color="blue" class="small">( The tires that go to the manufacturers for OEM on new vehicles have the very tightest tolerances. The very same label tire that falls outside of that range but still in an acceptable range goes to the tire dealer. That's why OEM tires always seem to last longer and ride better than replacements.
As to the "off-brand" tires being appearing to be superior to the branded tires, the reason is simple - They are! Someone like Sears has such incredible clout as a customer that they can and do negotiate not only better pricing but also better tolerances on their tires as well.
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I'd noticed that very thing and complained about it to a buddy of mine. I have a 2002 Corvette Z06 that when I got it new was practically glued to the road. It pulled > 1 G through turns like I was going to the grocery. I got a screw in a rear that did a number on it at about 50% wear, and had to replace the whole set because you DON'T mix and match with that car. I tried just replacing the rears and it drove worse than honda with loose front wheels. I replaced the fronts 2 days later, but I noticed that the car didn't have quite the grip and feel that it did on the tires I just replaced @ 50% wear. I was not happy.
I agree that "weather cracking" is most likely heat + low pressure cracking. The low pressure helps make the heat, so does carrying heavy loads.
Some "off brands" may be better because they aren't catering to OEM business. The Toyo Proxes T1 tires I put on the vette have done well - good rain performance over the oem, but not quite as much stick. We had Toyo M5 studded tires put on the truck for winter and they seem pretty good so far too.
If you go to TireRack or other places, you can do research to see what other people have said about the tires.
Sometimes stickier softer tires can last longer than harder compound tires. If the tire squeals a lot - you are over driving them and they will not last very long. I traded V rated tires for Z rated softer tires on my full-sized sedan and they stood up to my abuse for 5000 miles longer than the V rated, rode better AND stuck better in dry or wet AND I spent $4 less per tire (had to be ordered though).
Be prepared to have tires ordered to get what you want.
Me? It doesn't matter what vehicle its going on - I will trade traction for cash over long life and saving $$$ any day. My life, or my families lives, may be saved by that little extra stick.