Legal
Terms of use
4wd.ai provides research and calculation tools for planning. It does not inspect your vehicle or approve a modification.
No installation guarantee
Fitment depends on manufacturing tolerance, tire construction, alignment, load, wear, component combination and installation quality. You must verify clearance with a qualified installer before driving.
Safety responsibility
Vehicle modifications can affect steering, braking, electronic driver-assistance systems, payload, legal compliance and warranty coverage. Follow manufacturer instructions and applicable laws. Stop using a configuration that contacts safety-critical components.
Calculations
Calculator results use theoretical dimensions and should be treated as estimates. Actual tire measurements and speedometer behavior may differ.
External sources
Links are provided for evidence and context. 4wd.ai does not control third-party content, availability or product claims.
ChatGPT app
The 4wd.ai app in ChatGPT works out the same tire size comparisons as our calculator, under these terms: its figures are estimates from the nominal sizes, and its fit notes are a rule of thumb, not a fitment check. What it receives is in the privacy policy.
Contact
Questions about these terms, the site or the app: support@4wd.ai.