Long winded Tire Question !!!!!

Hey All !!!!
I have a set of Cooper tires, and I like them fine.
They Ride real nice and what not, but I'm having an issue with Tire pressure.
I'm trying to treat them nice so that I get the most life out of them as I can.
First of all.. the tag on the inside of my door jamb is incorrect from the factory. It references 15 in rims, however I have 16 in rims from the factory.
Apparently they only put the correct stickers on the "Limited" models.
At least that's what my research has told me. (as well as some of the folks on this site)
I'm trying to do the chalk test to check to see if I'm at a good pressure.
Note.. I did it in the morning when the tires were cool as is recommended.
And it shows I'm a little more round and wearing more at the center than the edges. (Overinflated)
HOWEVER ... with two different gauges all of my tires read 26 psi!!
The max pressure on the Tire itself is 44!
And, looking at the tires from the front and the back the profile looks good. They're not chubby on the sides which would indicate low pressure.
I attached a website pic of the tires just for reference.
I know this is a long-winded question but I wanted to give All of You Sage Souls as much info as possible.
Anyway, I'm curious as to what y'all think. Any wisdom is welcome!!!

 

There will always be more contact with the center of the tire than the edges. Sounds like your PSI may be a little low even though it doesn't look like it. Is it a SL/XL/E/C load tire?

My XL RT tires are good at 32-35psi, but it feels right at 34psi. Its a load and feel thing ultimately.

 

Could be that the tires were run oveinflated in the past but low on pressure now but I'm just guessing.

 

That could be. I know the kids they got at the tire places can be a mixed bag. When I went to go do my brakes I had to stand on the breaker bar with a cheater bar to break the lugs.
They love their impact guns

 

Hi Hank, We ran Coopers also, ours were AT3 LT in 275-70-17. They liked 37 PSI. we never did a chalk test, but we went with this tire for rock protection(10 ply rated), used to air down to 20-22 PSI for trail, liked them just fine. I don't know what to tell you about 26 PSI, it just seems a bit low, good luck.

 

Than ~35psi should be fine.

 

Yeah, I'm sure it was.
I may have been putting too much stock in the chalk test.
I went out this morning while my tires were cool and brought them all up to 35 PSI and I'll see what that looks like after a couple days of driving.
Thank you !!!

 

Ill share my experience with 285/70-17 SL Toyo AT3s on TRD Pro/SEMA wheels (7” wide)

I was reluctant to go this route because the wheels are technically too narrow for the tire (Toyo states 7.5” min.), but this seems to be a popular combination. The shop inflated them to like 36psi, and it felt like it was skating on ice. The shoulders had little to no contact except when cornering, was weird, no feeling off center then you could feel the tire grip when it rolled onto the shoulder in a turn.

Online tire pressure calculators said I could go as low as 26psi for equivalent load capacity as the stock tires at 32psi (recommended pressure). So I did the chalk test and found I couldn’t get shoulder contact until 27-28psi. Feedback was better, but handling got a little squirrelly. I compromised at 30psi.

5k miles later at 30psi, the center tread wore down to where the shoulders get better contact. I’m now at 32psi, and feels pretty good.

Another aspect to consider is suspension geometry. I’m lifted 2.5” so my alignment numbers (caster), while not terrible, are less than ideal. IIRC, I’m right at or just under min spec.

 

Interesting. I am the only owner of my SR5 4x4 and it came with 16" rims from the dealer (which are still on the car) and I didn't know that. I checked my tag and sure enough it references 15" rims. How odd.

 

Get a simple tread guage. (Amazon or auto parts store) Measure all tires center, inside , outside.
Evaluate readings which should reveal any wear pattern like center has less tread the both inside/outside.
Or post you tread thicknesson this site to see what other runner owners think.