315/70R17 vs 315/75R16
315/75R16 is a safe swap for 315/70R17 by the usual ±3% rule: the diameter differs by +0.70%.
Speedometer and odometer
With 315/75R16 on a car calibrated for 315/70R17, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.3 mph |
| 60 mph | 60.4 mph |
| 70 mph | 70.5 mph |
| 80 mph | 80.6 mph |
Other sizes close to 315/70R17
Questions
Can I replace 315/70R17 with 315/75R16?
315/75R16 is a safe swap for 315/70R17 by the usual ±3% rule: the diameter differs by +0.70%.
What's the difference between 315/70R17 and 315/75R16?
315/75R16 is 0.24" taller and 0 mm wider; the sidewall is +0.62". At an indicated 60 mph you'd actually be doing 60.4 mph.
Will 315/75R16 fit on 315/70R17 wheels?
No — 315/70R17 needs a 17" wheel and 315/75R16 a 16" wheel. This is a plus/minus-size swap that changes wheels too.