Forum Discussion

gitpicker2009's avatar
Mar 01, 2021

New Cooper tires behavior

I just installed 6 new Cooper tires on my Sterling 4500. These are the 19.5s.
I was replacing my old Dynatracs. The Dynatracs only had about 12K miles, but were 8 years old. I only use the truck for TC stuff generally. I never had a problem with the Dynatracs but the 4 rear wheels were "drive" wheels, different from the front "steer" wheels.

Now,at the advice of the tire dealer, the new Coopers are all steer wheels, so that I can rotate all the tires as needed. BUT... the truck now feels like I'm floating on a bubble. It's the only way to describe it. And, when you hit the brakes it feels VERY unstable. I've got the tires set at the same 80 PSI.
The dealer said that's normal and that the new tires would feel a bit "squirrelly" until I put about 500 miles on them.

Has anyone else dealt with this and if so, did it improve? I find it strange that the more expensive Cooper tires don't seem to drive as well as the cheap Dynatracs.

Thanks for any and all advice as always.

20 Replies

  • gitpicker2009 wrote:
    Is 80 PSI really considered low??? What do you recommend?


    19.5s are commercial tires. They have a different bead type than LT tires. They are designed for load and stability not flotation. you will lose the bead at low pressures

    Depending on the MFG, minimum inflation is between 70-80 psi with max up around 120psi

    look at the load inflation table for the roadmaster 245/70R19.5 on this table, It starts at 70psi
    http://roadmastertires.com/CooperRoadmaster/media/Documents/LoadandInflationTable.pdf
  • pianotuna wrote:
    Tire pressure too high may have the same effect, especially on the front wheels.


    80psi is about the minimum pressure that you can run 19.5s at without losing the bead
  • Both times with new 19.5's, they felt kind of drifty for nearly the first 1,000 miles and then it went away as they wore in. They're real stable now. I've had Hankooks and now Toyos. They drive pretty much the same. Mine were all aggresive tread. I'm on my second set now with a total of 205,000 miles.
  • Every time I get new tires, no matter the brand, it feels like I'm driving on ice. The last time which was only a few months ago I was very nervous on the freeway as it really seemed to skip and skate around. After a few days the feeling was gone and it was back to driving like normal.

    One thing that may be helpful is to realize that your new tires will behave differently than your old tires. When you drive you subconsciously move the steering wheel back and forth to correct for the road. Since your new tires will react differently than the old tires, the corrections you need to make are going to be different. This means that the speed and force that you apply to the wheel is going to be different and you might in fact be exacerbating the behavior because you are still steering for the old tires.

    Try taking it down the highway or freeway with a very light grip in the wheel. Let the truck drift a bit and use very small movements to keep it in line. Once you learn the idiosyncrasies of the new tires I'll bet you find them just as rock solid as the old.
  • Tire pressure too high may have the same effect, especially on the front wheels.
  • That's some scary sh!t.. I wonder how it will behave and what will happen In badly constructed highways.
  • I hated the "Steer" tires they floated and grab lips. Switched to Drive tires all around and the issue went away. That was Toyo steer. switched to Roadmaster drive tires by Cooper.
  • I believe it is “normal” for 19.5s to move around during break in and track groves in the road.