Does regearing affect Speedo/Odo?

Hey, guys, planning on a regear sometime in the future and also wanted to readjust and recalibrate the speedo/odo too. Just a quick question: Does regearing affect the speedometer/odometer? I heard from some that it does, but others say it doesn't. I have an automatic so the sensors are at the wheels (or something like that) instead of the transfer case (unlike a manual).

Can someone please clarify that for me? Does regearing affect the speedo/odo?
Thanks in advance.

 

Bump

 

No

 

Thank you for the clarification

Wait. Then what about the people that regearing would affect the speedo/odo??? Placebo effect?

 

Tire size, not gearing.

 

Manuals get the speed from the transmission so for us it will matter, since yours are from the wheels after the gears yours will be unaffected.

 

Tires will be the main factor here. I assume you are regearing due to tire size. The tools to correct speed do take into account tire size and gearing but tire size alone is going to mess that up big time.

 

All 3rd gens, no matter the transmission, get vehicle speed from wheel speed sensors. Therefore, any gearing change will not affect the speedo, but tire diameter change will.

 

Thanks for clarifying!

 

The speedometer and odometer numbers are really just based on counting wheel revolutions. Since the factory wheel diameter is known it is simple math to calculate speed and distance. When you go to a larger, or smaller diameter tire it messes up the math. That changes as tires wear down as well. A set of all terrain tires near the end of their useful life will be about 1" or one tire size, smaller than they were when they were new.