255/60R20 vs 33x12.50R20
33x12.50R20 is a safe swap for 255/60R20 by the usual ±3% rule: the diameter differs by +2.97%.
Side by side
| 255/60R20 | 33x12.50R20 | Difference | |
|---|---|---|---|
| Overall diameter | 32.05" | 33.00" | +0.95" (+2.97%) |
| Section width | 255 mm | 318 mm | +63 mm |
| Sidewall | 6.02" | 6.50" | +0.48" |
| Rim | 20" | 20" | same |
| Circumference | 100.7" | 103.7" | +3.0" |
| Revs per mile | 629 | 611 | -18 |
| Ride height | — | — | +0.48" |
| Speedometer reads 60 mph | 60.0 | 61.8 | +1.8 mph |
Speedometer and odometer
With 33x12.50R20 on a car calibrated for 255/60R20, the speedometer reads 58.3 mph when you're really doing 60, and the odometer under-counts by 3.0%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.9 mph |
| 45 mph | 46.3 mph |
| 60 mph | 61.8 mph |
| 70 mph | 72.1 mph |
| 80 mph | 82.4 mph |
Other sizes close to 255/60R20
- 255/60R20 vs 275/55R20-0.43%
- 255/60R20 vs 275/60R20+2.95%
- 255/60R20 vs 255/55R20-3.13%
- 255/60R20 vs 265/60R20+1.47%
- 255/60R20 vs 305/55R20+3.62%
- 255/60R20 vs 285/55R20+0.92%
- 255/60R20 vs 285/60R20+4.42%
- 255/60R20 vs 275/50R20-3.81%
- 255/60R20 vs 295/55R20+2.27%
- 255/60R20 vs 285/50R20-2.58%
- 255/60R20 vs 245/60R20-1.47%
- 255/60R20 vs 305/50R20-0.12%
Questions
Can I replace 255/60R20 with 33x12.50R20?
33x12.50R20 is a safe swap for 255/60R20 by the usual ±3% rule: the diameter differs by +2.97%.
What's the difference between 255/60R20 and 33x12.50R20?
33x12.50R20 is 0.95" taller and 63 mm wider; the sidewall is +0.48". At an indicated 60 mph you'd actually be doing 61.8 mph.
Will 33x12.50R20 fit on 255/60R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 318 mm tire and the fender clearance.