[Bammerman]

My spousal unit took her Prius to our local mechanic and complained that her car didn't seem to stop well esp. on wet leaves. (She did not believe me that this was the anti-lock mechanism activating.) They recommended new tires. I said she had plenty of tread left. The mechanic's sales rep gave me a song and dance. I took the car to a tire store and asked if new tires were needed. They felt the tires with their fingers and said No, these tires have lots of life left in them. Then I went to the auto parts store and spent $3 on a tire tread measuring tool, which found at least 5/32" of tread on the tires. Next I measured the (original) tires on my 2013 volt (34,000 miles) and again found at least 5/32" of tread left on them (tire store guys had also told me I did not yet need new tires on my Volt). Moral of story: buy yourself a $3 tire tread measuring tool and do it yourself!
Here are my questions:
1. Do you have and use one of these tools? (If not how do you keep track of your tire tread life?)
2. At what point (how many x/32" of tread left) should I replace my tires, really? (I know I need at least 2/32" but is that really enough for safe driving and stopping?)
Thanks guys (that is not a gender-specific term anymore, btw)

 

[AtomicPowered]

If you turn in a lease car the bank will want the tires replaced if they are at 4/32. Since it's the beginning of bad winter weather you may want to replace her tires in the interest of domestic tranquility.

 

[DonC]

Assuming the tires are still safe, agree that this is really a question of how long you intend to keep the car and how much tread is left. After a flat on the Volt I replaced mine before I needed to, but that was because I knew I was going to keep the car for a few more years and didn't see the point of selling a car with brand new tires. Ditto for the Leaf. I knew the tires would have to be replaced before turning the car in and figured it was better to replace and use rather than wait, replace, and then turn in.

The other factor is driving conditions. Deeper treads help in wet conditions. In dry conditions you're likely better off with less tread. (Not sure about wet leaves but probably you want more tread.) But for normal driving wet conditions are more worrisome than dry conditions. Where I am we don't get much rain, but when we do we get a fair amount and the roads have a lot of oil on them so conditions are definitely sub-optimal. Not to mention that people don't get much practice so aren't the best. Because of this, my approach is to err on the side of caution and replace when the tire gets to 4/32. My view. You may look at it differently.

I don't have a tool. I get a report every time the tires are rotated.

Short story: If I were in your situation, with a spouse who was concerned, at 5/32 I'd just replace the tires unless you were going to find the car a new home in the near future. She'll feel better and there won't be much time before replacing them.

 

[Rickoshay]

I had a sales rep at a national chain tire store measure my tread depth from the top of a wear indicator and inform me my tires needed replaced and they would not perform the free rotation they are so famous for. I asked him to remeasure. He did so as I was watching. Yep, right from a wear indicator. I left and will never purchase tires there that's for sure.

2014 Volt Premium - Safety pkg 1 and 2, Navigation

 

[Barry]

IMO, 5/32 is perfectly safe. Tread makes no difference on multiple layers of wet leaves. The leaves slide across each other, so your traction on the top layer doesn't help much. Most people replace somewhere between 4 and 2 (or when they fail the state inspection). If you detect any hydroplaning, replace right away.

 

[Sabuu]

1. Do you have and use one of these tools? (If not how do you keep track of your tire tread life?)
2. At what point (how many x/32" of tread left) should I replace my tires, really?

Yep, I have a tire tread measuring tool (and an analog air pressure gauge) - I store both of them in the door panel space on my 2014 Volt, as I figure if I'm ever going to need to measure the tire in some manner, I'll need one of those two tools and having them practically within arms reach at all times just made sense to me.
Personally, I agree with Berry. I try to aim for replacing at just before 3/32" or when you can detect hydroplaning/noticeable loss of handling during wet driving (whichever comes first, obviously).

For me, in my Prius, I replaced the FireStones that came with it at about 3.5/32" tread because one I was taking a rather tame left turn on some wet pavement one morning and mid turn I could feel the car trying to fishtail. Needless to say, got new tires the next day.

 

[Prohidium]

5/32 is not worn out. 2/32 is worn out. Considering some tires when new are only 8 or 9/32 when new, 5/32 is about half or slightly less life. There are some tires that are 11 or 12/32 when new but it all depends on compounds as to how long they take to wear down. Essentially, if you are above the wear indicators across the tire and all the way around on all 4 tires, you are good as long as the tires are not cracked or bulging or have other issues. The performance difference from new down to 2/32 is negligible with the exception of Ice/snow or deep water where deeper groves will help with hydroplaning or slightly more flex on the tread area for icy grip. Many do replace tires though at around this level as the tires do show signs of age and newer tires always seem to be better and offer piece of mind from a safety perspective. Of course, a new tire can blow out too!

 

[wizard_of-ahs]

I have a very sophisticated tire gauge.....it's called a penny
Put Lincoln's head in the tread, if the top of his head is visible...replace the tire.....tired gauge price $.01.

 

[Mister Dave]

Tire Rack's advice is that if rain and wet roads are a concern, you should consider replacing your tires when they reach approximately 4/32" of remaining tread depth.

https://www.tirerack.com/tires/tiretech/techpage.jsp?gclid=EAIaIQobChMIg7yi-YHn1wIVEEsNCh1T1w23EAAYASAAEgKYKPD_BwE&techid=157&s_kwcid=AL!3756!3!231171406279!e!!g!!when%20to%20replace%20tires&ef_id=WdhTOwAAAHOV_UX5:20171130191853:s

 

[Off Oil]

1. Yes, I use a quality digital gauge.
2. I change mine at 4/32. Given the copious amount of rain I need to deal with, I prefer the extra margin of safety. It's cheaper than collision repairs.

On wet leaves though, I doubt it would matter much with your depth. One just has to drive more cautiously with gradual takeoff and braking. I fortunately no longer have to deal with snow, but if I did again I would also use snow tires in the winter, and not rely on all-season versions.

 

[Bammerman]

$0.01 vs. $3.00

I have a very sophisticated tire gauge.....it's called a penny
Put Lincoln's head in the tread, if the top of his head is visible...replace the tire.....tired gauge price $.01.

I know about this and about using a quarter too, but I just couldn't see very well due to the tire position, shadows, etc. The advantage of the tread measuring tool is that you can put it against the tire, measure, then lift it away and read it comfortably and accurately in better light. At $3, I think it's worth it.