Replace tires at 4/32" depth?

What’s the feeling, is this a solid safety recommendation, or a way to sell more tires?
(Should I wait till next fall near snow time?)

4/32 wait unless other wear like uneven tread wear or age indicates otherwise.
BUT…be forewarned now and start saving up to be ready.
2/32 replace today.

Also depends greatly on the tread design of that tire.

In many many tread designs, the sipes and spaces between the tread blocks are long gone by now and you certainly do NOT have the same grip now as when the tire was new.
Look closely at a new tire and you’ll see on many that the greatest number of spaces and sipes do not continue all the way down as far as the deepest channels. That fact greatly changes the way the same tire handles as it wears. The tread actually does change with wear.

If you’re measuring in a channel or two and all the rest is smooth rubber…well then.
It really is a look and see situation and not a one answer fits all.

Once you go below 4/32", your wet handling starts to deteriorate so a lot depends on your driving style and weather conditions. At 4/32" it isn’t that noticeable, for me, at 3/32" it becomes more noticeable. At 2/32" it becomes a must change.


I do not like to replace tires in the spring or early summer. New tires tend to heat up more and heat is not good for tires. I prefer to change them in the fall or early winter where the extra heat is canceled by the cold of winter.


Before you replace your tires, check the condition and wear patterns of the treads. If it is flat and even, then don’t make any changes. If there is a distinctive wear pattern, then make the changes in alignment or tire pressure as needed.

If you drive a lot of miles you’ll wear down the treads in a few months. 2/32 is the legal limit in many states and that is when you’ll be down to the wear bars across the tread of the tire. At 4/32 I am not buying yet, but not going to get down below 3/32 so I’m shopping for good prices.

If you drive a lot in the rain and sometimes hit puddled water at interstate speeds you really are chancing it at 4/32 and below as far as hydroplaning is concerned. Snow traction won’t be good either, but a hydroplaning incident at 65 mph now thats something to consider. In the rain I’d keep my speeds down to about 55 and no more if you are running 4/32 tread tires.

Replace your tires when any portion of the wear indicator bars are even with the remaining tread. That is the recommendation of the tire mfrs. who I am confident have plenty of hungry trial lawyers ready and willing to second guess their judgement. The wear indicator bars can be made to indicate wearout at any desired tread depth when the transition from safe to unsafe becomes more apparent. Hydroplaning commonly happens and means that you must reduce your speed. If the safe speed becomes too low for you, then replace your tires. As tire treads approach wearout, the rate of wear decreases so you might have some useful life remaining in your tires.

I have good prices–a rebate of $70 on a set of 4. Not huge, but…

The OP has to realize that tread wear is not like an “on-off” switch, with the tires being absolutely safe at…let’s say…4/32, and suddenly unsafe at 3/32.

Tire traction on a slippery surface is more of a continuum, and it decreases steadily as the tread wears, thus, you already have reduced traction to some extent by the time the tread is worn to…let’s say…8/32. Then it is further reduced at 7/32, reduced still more at 6/32, and so on.

As Keith pointed out, much of the decision about when to replace your tires is dependent upon whether you typically have to deal with wet roadways. If rain is a fairly common occurrence in your area, 4/32 is a good point at which to replace those tires.

Absolutely VDC…and to expand a little on Keith’s comments, the replacement depends upon your use and the tread design of the tire. You can successfully run bare tires on a dry race track. Yet, in spring heavy wet snow, some snow tires give up when half worn at 7/32 and some not at all with smaller lugs. So as pointed out, it’s not only a continuum, but one based upon projected use and tread design.

This is a big reason why those of us who use separate winter tires on rims, can spend less on tires over the life of a car. We can run our summer all season tires down to 3 or 4/32 and not worry about their loss of snow traction. I feel the wear indicators are a sound guide to go by too. The exception might be those whose demands exceed the tire performance and might want to change early.

When you start hydroplaning its likely time or slow way down.

Otherwise before next winter if snow flies in your area.

Unfortunately as I do not want to do the maths, my tires were rated as need replacement soon at 5mm. I decided to let it go until I judged how well they did in the snow. They did fine, and as I tend to own my vehicles many years I get chap sometimes. !2k per year, so If I get 6 years instead of 5 it will save money in the long run, but compromising safety is more of a concern than saving money. As it stands, I was near convinced I needed tires before winter, but it was a mild winter and will probably get the extra 5k miles and replace them in the fall. I think they will do fine for the sand launch at the cabins for the boat, but have to admit If I were recommending my recommendation is don’t take a gamble for saving a few bucks.

By the time the tread is worn at any point down to the wear bars, you’re already driving on dangerous tires. One heavy rain, one hydroplane, and the resulting crash will cost you more than the $50 worth fo rubber you would have “thrown away” if you’d not tried to squeeze out the maximum mileage from what is probably the single most critical safety device you have…your tires. It may even cost a life.