I'm down to 6/32" on my rears and 7/32" on the fronts on my OEM Continental ContactSports after 8,000 miles (C2 cab).

The car never sees snow (they're summer tires), so we're talking just mostly dry days with only an occasional rainy day or two.

Assuming the tread wear is even, how far down is considered the practical point at which most of you buy new rubber. I know the legal limit (2/32" in Maryland), but wouldn't ever allow the tires get down to that point.

Is there a general rule of thumb as to where the performance/safety begins to degrade above the 2/32" legal limit?

Haven't yet decided what I'll replace them with and I know the threads on that subject are many, but I didn't see anything specific to the tread depth question.

Kevin

 

Look at the tread wear indicator on the tires.

 

I don't think there is any rule of thumb, but the closer to the wear bars the more trouble you'll have in water (rain). In a drizzle or damp road at low speed, just about any tread is probably ok, but your tread depth needs to exceed the amount of water depth (since some water is forced into the grooves by the tread that's intended to be on the ground. So the lower the depth, the greater the chance of some planing. If you're not out in the rain, or driving at speed on wet roads, it might be ok. Otherwise, why risk it? Just get some new shoes and don't worry about it.

For me, its just a matter of whether I feel comfortable and safe on them. Certainly if I have a planing incident in light rain I'm going to start shopping, but I usually replace my tires a bit early because we can get some hefty downpours here and I drive mostly above 70 MPH. Your situation may be different...

 

At that rate, you have another 8k miles to go on the rears before getting to the wear bars (2/32). At what point owners replace apparently varies; some at the wear bars, and others at 4/32. Even my own replacement points have varied between those points. Some tires are still working pretty well at 2/32 (except for evacuating water), while others I'll want to replace at 4/32; or even earlier (bad tires never seem to wear out). Whatever would make you most comfortable is probably the right thing to do.

 

My Pirellis are at the wear bars and the darn things are handling better than they did new. Don't drive the Porsche in the rain so I'm going to get a get couple of more road trips in before replacing them.

 

Some people use the quarter trick. Place a quarter on the worst area of the tread (not the crossbar wear indicators obviously) and if you place the quarter into the tread and see anything above Washington's head then you are getting too thin.

Realistically on the rears, your inside area will wear significantly higher than the outside due to proper factory negative camber settings,--that's where you should be looking.

 

+1