265/50R20 vs 275/55R20 at a glance
| Measure | 265/50R20 (current) | 275/55R20 (new) | Difference |
|---|---|---|---|
| Overall height | 30.43 in | 31.91 in | +1.48 in (+4.85%) |
| Width | 10.43 in (265 mm) | 10.83 in (275 mm) | +10 mm |
| Sidewall | 5.22 in | 5.95 in | +0.74 in |
| Wheel | 20 in | 20 in | +0 in |
| Circumference | 95.6 in | 100.2 in | +4.6 in |
| Revs per mile | 662.7 | 632.0 | −30.7 |
Verdict: check clearance and speedometer
Over 3% and up to 5%: worth checking clearance, the speedometer and gearing before you buy. Going from 265/50R20 to 275/55R20 is a 4.9% increase in overall height (+1.48 in), and the vehicle sits about 0.74 in higher. The tire is 10 mm wider. The 3% rule of thumb comes from Discount Tire and 1010tires; it is not a guarantee of fit.
True speed and odometer
| Speedometer shows | You are really doing | Difference |
|---|---|---|
| 35 mph | 36.7 mph | +1.7 mph |
| 45 mph | 47.2 mph | +2.2 mph |
| 55 mph | 57.7 mph | +2.7 mph |
| 60 mph | 62.9 mph | +2.9 mph |
| 65 mph | 68.2 mph | +3.2 mph |
| 70 mph | 73.4 mph | +3.4 mph |
| 75 mph | 78.6 mph | +3.6 mph |
Odometer: 1,000 indicated miles is 1,049 real miles, and 10,000 is 10,485.
The math
265/50R20: 20 + 2 × (265 × 50% ÷ 25.4) = 30.43 in. 275/55R20: 20 + 2 × (275 × 55% ÷ 25.4) = 31.91 in. Change = 31.91 ÷ 30.43 − 1 = +4.85%. True speed at 60 = 60 × 31.91 ÷ 30.43 = 62.91 mph.
Check next
- Regear and RPM at cruise for this swap
- Speedometer and odometer correction
- Other sizes within ±3% of 265/50R20
Calculated from the size alone. Real tires vary a little by brand and model, and the loaded radius is a bit smaller. Confirm the wheel width range, clearance, load index and speed rating for your vehicle. See how to read a tire size, the load index chart and the speed rating chart.
Size pages: 265/50R20 · 275/55R20. More swaps: all tire size comparisons.