315/70R17 vs 35x12.50R17
35x12.50R17 is a safe swap for 315/70R17 by the usual ±3% rule: the diameter differs by +1.86%.
Side by side
| 315/70R17 | 35x12.50R17 | Difference | |
|---|---|---|---|
| Overall diameter | 34.36" | 35.00" | +0.64" (+1.86%) |
| Section width | 315 mm | 318 mm | +3 mm |
| Sidewall | 8.68" | 9.00" | +0.32" |
| Rim | 17" | 17" | same |
| Circumference | 108.0" | 110.0" | +2.0" |
| Revs per mile | 587 | 576 | -11 |
| Ride height | — | — | +0.32" |
| Speedometer reads 60 mph | 60.0 | 61.1 | +1.1 mph |
Speedometer and odometer
With 35x12.50R17 on a car calibrated for 315/70R17, the speedometer reads 58.9 mph when you're really doing 60, and the odometer under-counts by 1.9%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.6 mph |
| 45 mph | 45.8 mph |
| 60 mph | 61.1 mph |
| 70 mph | 71.3 mph |
| 80 mph | 81.5 mph |
Other sizes close to 315/70R17
Questions
Can I replace 315/70R17 with 35x12.50R17?
35x12.50R17 is a safe swap for 315/70R17 by the usual ±3% rule: the diameter differs by +1.86%.
What's the difference between 315/70R17 and 35x12.50R17?
35x12.50R17 is 0.64" taller and 3 mm wider; the sidewall is +0.32". At an indicated 60 mph you'd actually be doing 61.1 mph.
Will 35x12.50R17 fit on 315/70R17 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.