True speed
Shows actual speed for any indicated speed, since a taller tire travels farther per revolution.
Speedometer correction
Check your Tacoma speedometer error.
Compare your stock and new tire size to see how far off the speedometer reads and your true speed at any indicated speed.
What it does
How this tool helps.
Percent error
Reports the speedometer error and flags whether it is inside the roughly 3 percent safe window.
Gearing note
Explains that a regear does not change speedometer error; only tire diameter does.
Related tools and guides
Speedometer Correction Calculator FAQ.
Bigger tires make the speedometer read low. The truck travels farther per wheel revolution than the factory calibration assumes, so your actual speed is higher than the number shown.
Within about 3 percent is considered excellent and usually not worth correcting. Beyond about 5 percent is where most owners recalibrate for accuracy and to keep the odometer honest.
No. The Tacoma speed sensor reads at the wheel hub, so tire diameter causes the error and axle gears do not change it. Recalibrate with a tuner or dealer tool instead.