33x12.50R17 vs 275/70R18
275/70R18 is a safe swap for 33x12.50R17 by the usual ±3% rule: the diameter differs by +0.48%.
Side by side
| 33x12.50R17 | 275/70R18 | Difference | |
|---|---|---|---|
| Overall diameter | 33.00" | 33.16" | +0.16" (+0.48%) |
| Section width | 318 mm | 275 mm | -43 mm |
| Sidewall | 8.00" | 7.58" | -0.42" |
| Rim | 17" | 18" | +1" |
| Circumference | 103.7" | 104.2" | +0.5" |
| Revs per mile | 611 | 608 | -3 |
| Ride height | — | — | +0.08" |
| Speedometer reads 60 mph | 60.0 | 60.3 | +0.3 mph |
Speedometer and odometer
With 275/70R18 on a car calibrated for 33x12.50R17, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.5%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.3 mph |
| 70 mph | 70.3 mph |
| 80 mph | 80.4 mph |
Other sizes close to 33x12.50R17
- 33x12.50R17 vs 265/70R17-4.22%
- 33x12.50R17 vs 285/70R17-0.88%
- 33x12.50R17 vs 245/75R17-4.64%
- 33x12.50R17 vs 235/80R17-3.63%
- 33x12.50R17 vs 285/75R16-0.51%
- 33x12.50R17 vs 315/70R17+4.13%
- 33x12.50R17 vs 255/75R17-2.85%
- 33x12.50R17 vs 295/70R17+0.79%
- 33x12.50R17 vs 33x12.50R180.00%
- 33x12.50R17 vs 305/70R16-0.57%
- 33x12.50R17 vs 285/75R17+2.52%
- 33x12.50R17 vs 275/70R17-2.55%
Questions
Can I replace 33x12.50R17 with 275/70R18?
275/70R18 is a safe swap for 33x12.50R17 by the usual ±3% rule: the diameter differs by +0.48%.
What's the difference between 33x12.50R17 and 275/70R18?
275/70R18 is 0.16" taller and 43 mm narrower; the sidewall is -0.42". At an indicated 60 mph you'd actually be doing 60.3 mph.
Will 275/70R18 fit on 33x12.50R17 wheels?
No — 33x12.50R17 needs a 17" wheel and 275/70R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.