Is it time to replace Cup 2R Tires

[Ramsman]

My 5BW came with Cup 2R tires as part of the Precision Package. I don't plan on tracking the car (at least anytime soon) so I plan to replace them with the Pilot Sport 4S tires. I was hoping they would last maybe a year. I don't know how many miles I should expect to get from the Cup 2R tires with just street driving, but I have almost 3000 miles so far. I just looked at the tires and measured the tread depth. The tires have 3 grooves. On the front tires all three grooves are still pretty deep (6/32" - 7/32"). On the rear tires, the 2 inner grooves are the same, but the center groove (outer most) is only around 3/32" deep.
This is the first time I have looked that closely, but I assume the rear center grooves were deeper at some point and are just wearing faster, maybe an alignment problem. Is it time for new tires or might I get a few more thousand miles on them? It's almost time to put the car away for the winter but Cadillac has a tire special through November, and I am wondering if I should just go ahead and replace them now even though the front tires look fine. Does anyone else have the Cup 2R tires that have only been street driven? How many miles are people getting and are they wearing similarly?

 

[Z28]

I have them on my daily driven ‘26 and noticed when new that one of the tread grooves is simply not as deep as the others. What I plan to do is just run them down to the wear bars and that will be my signal to replace.

What I want to know is whether I should go to a 285 PS4S in the front (with 305 TPCs in the rear) or stick with the factory TPC 275s in front. Once you open up to the idea of an alternative 285 non cup 2R front then I struggle to decide what’s the best combo or choice all around.

 

[nordique14]

Tread depth is important for evacuation of water. So it depends on if you plan on taking your car out in more than just a damp surface. If so, then 3/32” is a bit on the marginal side.

This article explains tread depth. Note that it is from a website whose main purpose is to sell tires so it may be on the more aggressive side when it comes to recommend tire replacement. But the theory still stands about a certain amount of tread being needed for safe rain/snow use.

https://www.tirerack.com/upgrade-garage/how-much-tread-depth-is-enough

 

[Ramsman]

Thanks! I'm glad to hear that the one groove on the rear tire may have never been as deep. I wondered that at first, but the front tire grooves seemed fairly consistent. They are all still above the wear marks but the one groove in the rear tires is much closer to the marks then the other rear tire or any front tire grooves.

Also, I never drive the car when there is rain in the forecast with these tires. I hope for dry days above 40 degrees for a while longer before winter.