33x12.50R20 vs 275/65R20
275/65R20 is outside the ±3% rule as a replacement for 33x12.50R20: the diameter differs by +3.26%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Side by side
| 33x12.50R20 | 275/65R20 | Difference | |
|---|---|---|---|
| Overall diameter | 33.00" | 34.07" | +1.07" (+3.26%) |
| Section width | 318 mm | 275 mm | -43 mm |
| Sidewall | 6.50" | 7.04" | +0.54" |
| Rim | 20" | 20" | same |
| Circumference | 103.7" | 107.0" | +3.4" |
| Revs per mile | 611 | 592 | -19 |
| Ride height | — | — | +0.54" |
| Speedometer reads 60 mph | 60.0 | 62.0 | +2.0 mph |
Speedometer and odometer
With 275/65R20 on a car calibrated for 33x12.50R20, the speedometer reads 58.1 mph when you're really doing 60, and the odometer under-counts by 3.3%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.0 mph |
| 45 mph | 46.5 mph |
| 60 mph | 62.0 mph |
| 70 mph | 72.3 mph |
| 80 mph | 82.6 mph |
Other sizes close to 33x12.50R20
- 33x12.50R20 vs 275/55R20-3.30%
- 33x12.50R20 vs 275/60R20-0.02%
- 33x12.50R20 vs 265/60R20-1.46%
- 33x12.50R20 vs 305/55R20+0.63%
- 33x12.50R20 vs 285/55R20-1.99%
- 33x12.50R20 vs 285/60R20+1.41%
- 33x12.50R20 vs 295/60R20+2.84%
- 33x12.50R20 vs 295/55R20-0.68%
- 33x12.50R20 vs 285/65R20+4.81%
- 33x12.50R20 vs 245/60R20-4.32%
- 33x12.50R20 vs 305/50R20-3.01%
- 33x12.50R20 vs 255/60R20-2.89%
Questions
Can I replace 33x12.50R20 with 275/65R20?
275/65R20 is outside the ±3% rule as a replacement for 33x12.50R20: the diameter differs by +3.26%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 33x12.50R20 and 275/65R20?
275/65R20 is 1.07" taller and 43 mm narrower; the sidewall is +0.54". At an indicated 60 mph you'd actually be doing 62.0 mph.
Will 275/65R20 fit on 33x12.50R20 wheels?
Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.