33x12.50R18 vs 255/80R17
255/80R17 is a safe swap for 33x12.50R18 by the usual ±3% rule: the diameter differs by +0.19%.
Side by side
| 33x12.50R18 | 255/80R17 | Difference | |
|---|---|---|---|
| Overall diameter | 33.00" | 33.06" | +0.06" (+0.19%) |
| Section width | 318 mm | 255 mm | -63 mm |
| Sidewall | 7.50" | 8.03" | +0.53" |
| Rim | 18" | 17" | -1" |
| Circumference | 103.7" | 103.9" | +0.2" |
| Revs per mile | 611 | 610 | -1 |
| Ride height | — | — | +0.03" |
| Speedometer reads 60 mph | 60.0 | 60.1 | +0.1 mph |
Speedometer and odometer
With 255/80R17 on a car calibrated for 33x12.50R18, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.1 mph |
| 60 mph | 60.1 mph |
| 70 mph | 70.1 mph |
| 80 mph | 80.2 mph |
Other sizes close to 33x12.50R18
- 33x12.50R18 vs 275/65R18-2.80%
- 33x12.50R18 vs 275/70R18+0.48%
- 33x12.50R18 vs 285/70R17-0.88%
- 33x12.50R18 vs 265/65R18-4.35%
- 33x12.50R18 vs 265/70R18-1.19%
- 33x12.50R18 vs 255/70R18-2.86%
- 33x12.50R18 vs 285/65R18-1.25%
- 33x12.50R18 vs 295/70R18+3.82%
- 33x12.50R18 vs 295/70R17+0.79%
- 33x12.50R18 vs 285/60R18-4.65%
- 33x12.50R18 vs 33x12.50R170.00%
- 33x12.50R18 vs 325/65R18+4.95%
Questions
Can I replace 33x12.50R18 with 255/80R17?
255/80R17 is a safe swap for 33x12.50R18 by the usual ±3% rule: the diameter differs by +0.19%.
What's the difference between 33x12.50R18 and 255/80R17?
255/80R17 is 0.06" taller and 63 mm narrower; the sidewall is +0.53". At an indicated 60 mph you'd actually be doing 60.1 mph.
Will 255/80R17 fit on 33x12.50R18 wheels?
No — 33x12.50R18 needs a 18" wheel and 255/80R17 a 17" wheel. This is a plus/minus-size swap that changes wheels too.