235/65R17 vs 265/60R18
265/60R18 is +5.1% away from 235/65R17 on rolling diameter, well outside the 3% substitution rule. Expect rubbing at full lock or under compression unless the arches have been modified, plus 19.0 mm of extra radius to house. Speedometer and odometer error at this magnitude is large enough to matter for warranty mileage and for anything measured from wheel speed. Treat this as a modification, not a substitution.
- Diameter change
- +5.14%
- +37.9 mm
- Ride height
- +19.0 mm
- half the diameter change
- Tread width
- +30 mm
- 265 mm section
- Speedo at 60
- 63.1
- true mph when the dial reads 60
Side by side
| Measure | 235/65R17 | 265/60R18 | Change |
|---|---|---|---|
| Overall diameter | 29.03″ | 30.52″ | +5.14% |
| Section width | 235 mm | 265 mm | +30 mm |
| Sidewall height | 152.8 mm | 159.0 mm | +6.3 mm |
| Rim diameter | 17″ | 18″ | +1″ |
| Revolutions / mile | 695 | 661 | −34 |
Questions about this swap
›Can I fit 265/60R18 instead of 235/65R17?
Only with care. The diameter differs by +5.1%, outside the 3% rule, so clearance and speedometer accuracy both need checking first.
›How much will my speedometer be out with 265/60R18 instead of 235/65R17?
By about 5.1%. At an indicated 60 mph you would actually be doing 63.1 mph, so the dial under-reads your true speed.
›Does fitting 265/60R18 change ride height from 235/65R17?
Yes, by roughly 19.0 mm. Rolling radius is half the diameter change, so the axle sits that much higher and you need the same amount of extra room above the tyre.
›Will my odometer read differently on 265/60R18 rather than 235/65R17?
It will read 5.1% low. Over 10,000 recorded miles that is about 514 miles of difference against the true distance travelled.
Want to try other sizes? Open the calculator.