ethang1977

wow! 65psi. how's the ride?

Canadian Jker

Great they feel like street tires, dont feel the lugs hitting or anything.

Widewing

Great! Only 30 psi above recommended pressure. You realize that this is probably well above the maximum for the tire? So, when one fails in a most violent manner, just chalk it up to Darwin's theory at work.

toymaster

Dude. He did mention the load range of D. Since you do not know... not all tires require 30 psi. It depends on the structure of the tire and the intended weight rating. Also I might add that the psi given is a MAXIMUM cold air pressure. On my F550 the tires take 95 psi to handle the max weight rating .

The only way to know for sure is to read it on the tired itself, that is why it is molded into the tire in the first place.

Widewing

I've never seen a load range D tire rated higher than 65 psi maximum. MAXIMUM! So, you gents figure that because it says 65 psi, "shit, lets just air it up to that", right?

From a pretty good source: "A tire's maximum inflation pressure is the highest "cold" inflation pressure that the tire is designed to contain. However the tire's maximum inflation pressure should only be used when called for on the vehicle's tire placard or in the vehicle's owners manual."

Running his tires at the maximum leaves little margin. Bad idea, especially as there is absolutely no logical reason to do so on vehicle weighing less than 2 tons.

So, how big is the contact patch at 65 psi? How about tread temperature? Did he check it with a pyrometer? How about a simple chalk test?

I'm running 285/70-17s in load range D... I run them between 33 and 35 psi cold. I found this to be best for maintaining uniform tread temperature, which I checked with a pyrometer after heating them to normal operating temps on a 15 miles highway run.

Anyway, "Dude", please explain why running 30 psi above recommended pressure is a good idea.

Canadian Jker

Side wall says maximum 65 PSI on it. I run them at 65 in the winter and 60 in the summer and they have not heated up past 65.5 psi running down the highway on a hot day. Like i said tread wear is perfect and i have almost 50 000 km on them, ride quality is great as well.