Tread depth gauge implementation.

My in-laws got me a tread depth gauge for my birthday because I asked for one. Now I'm running around measuring the tread depth on all my tires, which is fun, but I need some science. How do I use this new tool to make my life better?
My inclination is to measure outside, middle, inside, record, and graph to look for trends. This might be overkill though. Is there a better way?

Yep. Sounds like overkill to me.

I used one to have a data point to record in vehicle maintenance records. I take an average reading, and write it down.

I also use it to see deth for shaving on new tires, and to communicate to buyers of used tires how deep the tread is. But that's about it.

I don't think you can use it for very detailed trending, because you are going to find some inconsistencies. Kind of like trying to measure milliseconds on a calendar.

If you rotate the tire, you will find differences in different locations on the tire. They don't cast them with perfectly even tread depth, and they wear unevenly and out of round (a little)

A temperature gauge can give you some specifics. A tread gauge is a little more vague.

In reply to SVreX:

I use mine mainly when swapping winter/summer tires to get the best on the drive wheels (FWD) where they will experience the most wear, and give me the most not get stuck ability for the winter and the most life out of the summer tires. Also used before going for state inspections, you never know when you will get a new guy who will only see the repair of the week and sees it everywhere. Unfortunately, the depth gauge is not good for disproving claimed worn steering components.

Agreed, sounds like overkill to me also, but it also sound like something I would have done in the past, take a reading every couple thousand and document, just to see the difference between the gauge and my eyes, and to feel like I was saving money. Now time is more important than the couple bucks I could save from the hours of readings, documentation, and rotations.

Steve

I use them to determine installation location when I swap winter/summer and summer/winter. Also when to put them for sale on CL (6/32).

I used to use mine to measure in/out/center to help determine tire pressure and camber.

But I'm way too lazy for that now. I mostly break it out before state inspections to see if my half-bald tires will pass.

I'm going to let out my tire-nerd here for a bit...

If you want to record/track/graph tread depth I'd recommend the following:

• Measure in all 3 (or 4) circumferential grooves plus a lateral slot in both the inside and outside shoulders. Try and make all of the measurement locations in the same 2-3" of the tire. (aka, as straight across the tread as possible)
• Measure each of these grooves in 3-4 places around the circumference of the tire
• Do all of these measurements about every 2-4,000 miles for detailed analysis. However, it might be easier to just do them every time you rotate the tires (every 5,000 miles on my cars).
• To assist in making these many measurements more accurate over time take a good paint pen and mark the measurement locations in the base of the grooves. The paint should last a while as it's not in contact with the road surface. Also, on the inner sidewall number (or letter) your 3-4 circumferential groups of measurements.
• When analyzing the data for each tire, get an average of each groove location value across the groups.
• As far as usable metrics to look at I'd suggest remaining tread depth and rate of treadwear. Rate of treadwear can be measured in thousandth's of an inch tread depth used per mile of distance covered. Getting even more detailed you could calculate an estimated mean treadwear value to try and predict how many miles of use are left in the tire based on the current rate of treadwear and remaining tread depth.

However, this all depends on how accurate your tread depth gauge is. The measurements I'm talking about are typically done with a set of calipers or a digital tread depth gauge that can measure to 0.001". It will be hard to get consistent, reliable measurements with a tread depth gauge that can only measure to the nearest mm. Remember, the total change in tread depth from new to worn out (2/32") is only about 9/32" (7.14 mm)

Just wait until it rains or snows. You'll know if you need tires.