Odometer/Digital Speedometer/Analog Speedometer factory tolerance? How are the two related?

Here's the service manual from 11-13-15.
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ohhh snap! So both the digital and analogue speedo and odometer come from the same source?! So yea I guess analogue is just way off...ohhh well.

Either way never really cared about my actual speed...just how it affected odometer. I just stay with the flow. I am concerned about milage and what could get me in trouble. If Toyota tolerance is 2 mph, I should be ok with 265/75/16’s.

 

@splitbolt thanks brother

 

You will never be perfect. There is an SAE J spec that all auto manufacturers adhere to and if I remember it's + - 2%. It's not perfect because tire pressure, tire wear, etc. While this spec was developed before GPS, you cannot rely solely on GPS for all applications because there are a lot of places where GPS does not work.
So, at 70mph it could be 68 mph or 72 mph. In addition, it could be you have really worn tires or a "big" diameter 265 65 16.
And, because of tolerances, my Speedo is probably different than your Speedo haha.

Truly this is an area where the expectation of accuracy is wasted.

 

@hiPSI well said. I understand now....thank you so much to all for the input and patience. I try to be as prescise as possible. I understand due to pressure, altitude, wear, size, it will never be truely accurate. I am really not concerned with speed as I don’t drive fast and am driving a truck....the best truck!

I was worried about how putting one size larger tires would effect my odometer reading. Not necessarilly for maintenance because even that schedule could not be equal as we all drive differently, use different fluids, etc..
Was more thinking of the legalities of putting on a larger tire and not having accurate mileage and also how it could affect warranty-I have the platinum warranty (Toyota gave it to me for free!) So contractually or legally I do not want to screw myself just for a little bigger tire.

 

I think the Speedo has to be tampered with before there is a problem. Just remember there is only one odometer on your truck. Even if you put really big tires on there then the mileage is only recorded on your odometer. There is no way for anyone to verify your odometer is wrong.

As far as having a free warranty? There is a reason the Toyot a warranty, even if you had to buy it, is one of the best and cheapest out there. They gave you something that they don't expect you to ever use. Sure, it's piece of mind but statistically very few owners ever NEED an extended warranty. See if Jeep or Jaguar will give you a warranty haha.

 

First, it is "precise".

Second, I think the best way to account for different size tires is to use the revs/mile spec for the specific tires you are comparing. This will give you the closest estimation of the difference. Unfortunately, you can't always find it online... maybe if you call the mfg? Tire size calculators are just ballpark numbers.

(You may notice the diameter calculated from the revs/mile is different than the published diameter. The published diameter seems to be the unloaded diameter.)

 

I think there is a reset in the radio for when you buy new tires, think it adjusts the Speedo accounting for wear. That would apply to stock tire size obviously.

 

There is; but, it for the navigation dead reckoning when it's not receiving/using gps data for current location.
There is no input from the head unit to the combination meter, except for the navigation feature.