Observed arrival · 2026-10-25
GearIron’s connected automotive calculators
A free set of automotive calculators for tire sizing, speedometer error, gearing, engine RPM, and related calculations.
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$Paid
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✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Truck, Jeep, and work-rig owners changing tire sizes
- Worth noticing
- The site says tire inputs carry through comparison, speedometer error, effective gearing, cruising RPM, and regear calculations.
Field notes
The homepage organizes the tools into tires and wheels, gearing and drivetrain, and engine clusters. Its tire comparison tool is described as handling up to ten sizes, while the crawl-ratio tool combines first gear, transfer-case ratio, and axle ratio and also gives distance per engine revolution. GearIron says formulas appear on each calculator page and that entered numbers remain in the browser.
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Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
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