235/65R18 vs 255/60R18Tire Size Comparison
The 0.1% diameter difference is within the accepted 3% tolerance.
Comparison Details
Speedometer Correction
When switching from 235/65R18 to 255/60R18, your speedometer will differ from actual speed.
| Speedometer | Actual Speed | Difference |
|---|---|---|
| 30 km/h | 30.0 km/h | 0.0 km/h |
| 40 km/h | 40.0 km/h | 0.0 km/h |
| 50 km/h | 50.0 km/h | 0.0 km/h |
| 60 km/h | 60.0 km/h | 0.0 km/h |
| 70 km/h | 70.0 km/h | 0.0 km/h |
| 80 km/h | 80.1 km/h | +0.1 km/h |
| 90 km/h | 90.1 km/h | +0.1 km/h |
| 100 km/h | 100.1 km/h | +0.1 km/h |
| 110 km/h | 110.1 km/h | +0.1 km/h |
| 120 km/h | 120.1 km/h | +0.1 km/h |
| 130 km/h | 130.1 km/h | +0.1 km/h |
Vehicles Using These Sizes
Vehicles with 235/65R18
Individual Tire Size Details
Practical Guidance
Switching from 235/65R18 to 255/60R18 is within the industry-accepted 3% diameter tolerance. Your speedometer, ABS, and traction control should function normally. Both sizes fit the same 18-inch rim, so no wheel change is needed.
The 3% diameter tolerance is a widely accepted industry guideline referenced by the ETRTO and most vehicle manufacturers. When in doubt, consult your vehicle's owner's manual or a qualified tire professional. For U.S. tire safety standards and recalls, see the NHTSA Tire Safety page.
Frequently Asked Questions
Safe. The overall diameter differs by 0.07%, width changes by 20mm.
Speedometer error will be 0.07%. At an indicated 100 km/h, actual speed is about 100.1 km/h.
Ground clearance changes by +0.3mm per side.