305/65R17 vs 33x12.50R17
33x12.50R17 is a safe swap for 305/65R17 by the usual ±3% rule: the diameter differs by +1.20%.
Side by side
| 305/65R17 | 33x12.50R17 | Difference | |
|---|---|---|---|
| Overall diameter | 32.61" | 33.00" | +0.39" (+1.20%) |
| Section width | 305 mm | 318 mm | +13 mm |
| Sidewall | 7.81" | 8.00" | +0.19" |
| Rim | 17" | 17" | same |
| Circumference | 102.4" | 103.7" | +1.2" |
| Revs per mile | 618 | 611 | -7 |
| Ride height | — | — | +0.19" |
| Speedometer reads 60 mph | 60.0 | 60.7 | +0.7 mph |
Speedometer and odometer
With 33x12.50R17 on a car calibrated for 305/65R17, the speedometer reads 59.3 mph when you're really doing 60, and the odometer under-counts by 1.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.4 mph |
| 45 mph | 45.5 mph |
| 60 mph | 60.7 mph |
| 70 mph | 70.8 mph |
| 80 mph | 81.0 mph |
Other sizes close to 305/65R17
- 305/65R17 vs 265/70R17-3.08%
- 305/65R17 vs 285/70R17+0.30%
- 305/65R17 vs 245/75R17-3.50%
- 305/65R17 vs 265/70R18-0.01%
- 305/65R17 vs 235/80R17-2.47%
- 305/65R17 vs 285/75R16+0.68%
- 305/65R17 vs 285/65R18-0.07%
- 305/65R17 vs 255/70R17-4.77%
- 305/65R17 vs 255/75R17-1.69%
- 305/65R17 vs 295/70R17+1.99%
- 305/65R17 vs 305/70R16+0.62%
- 305/65R17 vs 285/75R17+3.74%
Questions
Can I replace 305/65R17 with 33x12.50R17?
33x12.50R17 is a safe swap for 305/65R17 by the usual ±3% rule: the diameter differs by +1.20%.
What's the difference between 305/65R17 and 33x12.50R17?
33x12.50R17 is 0.39" taller and 13 mm wider; the sidewall is +0.19". At an indicated 60 mph you'd actually be doing 60.7 mph.
Will 33x12.50R17 fit on 305/65R17 wheels?
Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 318 mm tire and the fender clearance.