How Speedometer Difference Works
Learn how tire size changes can affect speedometer and odometer readings through diameter and revolutions per mile differences.
A vehicle speedometer estimates speed based partly on how many times the tire rotates over distance.
When tire diameter changes, the number of revolutions per mile changes, which may affect speedometer and odometer readings.
This remains theoretical because tire deflection, tread wear, load, and calibration affect real-world behavior.
Important reference note
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