Highway RPM
Calculates engine RPM at a range of speeds from tire diameter, axle ratio, and transmission gear.
Cruising RPM
Estimate your Tacoma highway RPM.
Enter tire size, axle ratio, and top-gear ratio to see cruising RPM and judge whether a regear is worth it.
In short
Estimates engine RPM at a road speed from tire diameter, axle ratio, and transmission top-gear ratio.
- Uses the standard RPM equation with the 336.135 constant derived from 63,360 inches per mile.
- Helps decide whether a tire or gearing change leaves the engine lugging or buzzing at highway speed.
What it does
How this tool helps.
Regear planning
Compare RPM before and after a tire change to see how much a numerically higher axle ratio would help.
Tacoma presets
Factory axle ratios and transmission top-gear ratios by generation are built in.