I have been running the max tire pressure on my cooper stt 37's for the first 5000 miles or so which I think is 65 psi and I was wondering if I should bump it down to around 40 psi or so, to help with tire wear and ride quality. Any one have an experience with this, they are range D and are a mud tread type tire. tow every weekend but could easily bump up the pressure to tow if needed too.

 

it would be less stiff if you aired them down. What rim width are you running them on?

 

The rim width is 8.5 or 9 inches I believe

 

I'd go with about 42-45 for best ride and wear imo

 

Sounds like a LR D with a max 65. Those have a max load of 3525lbs at 65. 40 should be fine for those on an F150.

 

thats what I thought because the middles are going to wear faster then the outside right now at 65 and I think the steering may seem to "tighten up" with the pressure down right now it kinda floats

 

Yeah you should notice a difference in ride. And yeah the center would most likely wear faster aired up like that because the contact patch is not evenly distributed.

 

Also, with less tire in contact with the road, it will give better gas mileage, but will have problems on wet roads etc, were more contact is better.