3.55 to 3.73?

[2TimingTom]

Tire construction today won't bulge the center of the tire noticeably until you really over inflate them- like 75-100 psi. At 40 psi vs 30 psi, the difference in contact patch will be seen from the side of the tire. 30 psi will have more tire on the ground in the front-to-back orientation than 40 psi.

 

[239]

How have your tires worn in the past? If they are noticeably more worn in the center, then the pressure is likely the issue. If they are evenly worn across the tread from edge to edge, lowering the pressure won't do too much. I used to run my old tires at 40 psi too, and never had your spinning issue, or had uneven wear.

They're actually worn at the inner edge, but that's before I replaced my control arms and lower ball joints, and that's the front tires. I lost traction at around 1500 rpm today. I'm going to try lower pressure, and if that doesn't work I'll have my mechanic look at the truck.

 

[239]

Tire construction today won't bulge the center of the tire noticeably until you really over inflate them- like 75-100 psi. At 40 psi vs 30 psi, the difference in contact patch will be seen from the side of the tire. 30 psi will have more tire on the ground in the front-to-back orientation than 40 psi.

I looked at the tires again and they were actually worn in the middle. I went down to 35 psi and it feels like a different truck. It feels like I have AWD and coil overs all around. Ok that's exaggerating But it does feel a lot better. I'm just waiting for some rain now to see if the spinning is gone. It definitely feels like I get a lot more traction when accelerating now and the ride is softer.