255/50R19 vs 275/45R20Tire Size Comparison
The 2.4% diameter difference is within the accepted 3% tolerance.
Comparison Details
Speedometer Correction
When switching from 255/50R19 to 275/45R20, your speedometer will differ from actual speed.
| Speedometer | Actual Speed | Difference |
|---|---|---|
| 30 km/h | 30.7 km/h | +0.7 km/h |
| 40 km/h | 41.0 km/h | +1.0 km/h |
| 50 km/h | 51.2 km/h | +1.2 km/h |
| 60 km/h | 61.5 km/h | +1.5 km/h |
| 70 km/h | 71.7 km/h | +1.7 km/h |
| 80 km/h | 81.9 km/h | +1.9 km/h |
| 90 km/h | 92.2 km/h | +2.2 km/h |
| 100 km/h | 102.4 km/h | +2.4 km/h |
| 110 km/h | 112.7 km/h | +2.7 km/h |
| 120 km/h | 122.9 km/h | +2.9 km/h |
| 130 km/h | 133.2 km/h | +3.2 km/h |
Vehicles Using These Sizes
Vehicles with 255/50R19
Vehicles with 275/45R20
Individual Tire Size Details
Practical Guidance
Switching from 255/50R19 to 275/45R20 is within the industry-accepted 3% diameter tolerance. Your speedometer, ABS, and traction control should function normally. Note: these sizes require different rim diameters (19" vs 20"), so you will need different wheels.
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 2.43%, width changes by 20mm.
Speedometer error will be 2.43%. At an indicated 100 km/h, actual speed is about 102.4 km/h.
Ground clearance changes by +8.9mm per side.