245/60R18 vs 255/65R18Tire Size Comparison
The 5.0% diameter difference exceeds 3% and may affect speedometer accuracy.
Comparison Details
Speedometer Correction
When switching from 245/60R18 to 255/65R18, your speedometer will differ from actual speed.
| Speedometer | Actual Speed | Difference |
|---|---|---|
| 30 km/h | 31.5 km/h | +1.5 km/h |
| 40 km/h | 42.0 km/h | +2.0 km/h |
| 50 km/h | 52.5 km/h | +2.5 km/h |
| 60 km/h | 63.0 km/h | +3.0 km/h |
| 70 km/h | 73.5 km/h | +3.5 km/h |
| 80 km/h | 84.0 km/h | +4.0 km/h |
| 90 km/h | 94.5 km/h | +4.5 km/h |
| 100 km/h | 105.0 km/h | +5.0 km/h |
| 110 km/h | 115.5 km/h | +5.5 km/h |
| 120 km/h | 126.0 km/h | +6.0 km/h |
| 130 km/h | 136.5 km/h | +6.5 km/h |
Vehicles Using These Sizes
Vehicles with 245/60R18
Vehicles with 255/65R18
Individual Tire Size Details
Practical Guidance
The 5.0% diameter difference between 245/60R18 and 255/65R18 exceeds the standard 3% tolerance. While physically possible, this change will cause noticeable speedometer error and may affect ABS and traction control calibration. Consult a tire professional before making this switch.
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
Use Caution. The overall diameter differs by 4.99%, width changes by 10mm.
Speedometer error will be 4.99%. At an indicated 100 km/h, actual speed is about 105.0 km/h.
Ground clearance changes by +18.8mm per side.