Is there a size limit to the "Tire change calibration"

In September of 2022 I purchased a set of 265/75r16 KO2's. I had done the calculations and new that if I was going 65mph it would read 67.5. But for shits and giggles I went into the navigation settings and pressed the button for the "Tire Change" When I was on a long road trip in November I used the GPS on my phone to check the speed of my truck when I had cruise set to 70 mph and google maps showed 70 mph. Coincidentally it was also confirmed when I had the cruise set to 85 mph by a CHP.

So two independent sources showed that the 31.7 inch tire had not affect on the accuracy of my speedometer.

What I am wondering is if this works for any tire size?

 

It is common that with stock size tires at 60 mph or so you are most likely only going 57. When I went from the 265/70/16 to 265/75/16 my speedometer was right on. But then that will leave you with no margin. So to sum it up going up one size made it more accurate. But know with my 285/75/17's I am going closer to 75 when speedo is reading 70.

 

hmm didn't know that "tire change" thing existed.

 

Do you have factory Nav on your truck? And if so did you press the "tire change" button?

And I am skeptical of your statement because while driving my 2023 Tacoma with stock 265/70r16 tires on the freeway with cruise set to 70 mph, I verified the speed with google maps as well and it was accurate.

 

It calibrates the navigation unit not the speedometer and computer.
You need an in line calibrating device by hypertech.

 

And yet I didn't.

 

Most manufacturers over report speed by a few mph from the factory. You bumping up +1 in tire size basically corrected that offset. To truly see the difference, you would need a before swap comparison measurement.

 

My 2023 speedo is accurate with stock tires.

 

So…. Accurate by gps with stock tire size, then accurate by gps with +1 tire size?

 

You must have an anomaly, because I have never seen a Tacoma that reads accurately on stock tires. They read accurately when they step up 1”.

Without doing anything to the Nav button. Not calling you a liar, but this has been observed on tons of Tacomas. It provides a speeding buffer. My own Tacoma had 265/70/17 when I got it and read right on the dot, and now that I went back to 265/65/17, it’s off by 2-3 mpg at highway speed.

 

I think he’s thinking messing with the Nav button on his radio made a difference.

That said, I have an aftermarket radio and didn’t have Nav or the button ever and still don’t and my Speedo was accurate on 265/70/17, and was 2-3 mph fast on the stock 265/65/17s. That is how every Tacoma I’ve observed behaves and most on TW say the same. So not sure what’s going on in this case unless the gps was not accurate when testing on the stockers.

 

I tried the nav calibration steps when I went to 285s and didn't work for the speedometer. Its been discussed before.

 

Considering your new tire size isn't much taller than stock, your speedo won't be noticeably different

 

It's tall enough that at 70-85 miles per hour it will register about 3 mph off.

 

When you guys say your speedo is off are you talking about the analog dial, or the digital display?

 

Every Toyota we've ever owned (Sienna, Corollas, T-100, Tacoma) has been off by about 2mph.
We just assume it's the Toyota speed buffer.

 

I went from 215.15 to 235.15 tires and it made the speedo perfect.

 

Do any of you have factory navigation?

 

Ok, to clarify a lot of misinformation and bad assumptions going on here:

• The "tire change" button has absolutely nothing to do with speed calibration. That button is for updating/pinging TPMS sensor locations after a rotation.
• All vehicles come from the factory with an acceptable margin of error on speed calibration. That margin is bigger than you think. These speedos are not exactly laboratory grade precision instruments. Sometimes you get lucky and changing wheels gets it closer to calibration than it was at factory.
• You cannot calibrate the Speedo on your own (with caveats). Messing with the speedometer falls under odometer fraud, believe it or not, so you had better believe that Toyota is not going to make it easy. Most dealers will flat out refuse if you ask for speed calibration. It's a huge legal liability for them.
• The exception to that is that there is one gray -market (aka, not technically illegal, at least not in 49 states) solution, sold by two different brands. It's a little box that interrupts the speed input and puts out a different output, according to your tire size. This is the only way that you, the average consumer, can calibrate the speedometer.

 

This statement makes no sense.

What about people without factory navigation? And you think Toyota decided to put the the button to learn the location of each tire under the navigation advanced settings and not the tpms menu? Also why go with a central system and not just have relays ar each axle that feed the data from the tpms sensor that has limited range?