225/75R15 vs 225/70R16
225/70R16 is a safe swap for 225/75R15 by the usual ±3% rule: the diameter differs by +0.40%.
Speedometer and odometer
With 225/70R16 on a car calibrated for 225/75R15, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.4%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.1 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.2 mph |
| 70 mph | 70.3 mph |
| 80 mph | 80.3 mph |
Other sizes close to 225/75R15
Questions
Can I replace 225/75R15 with 225/70R16?
225/70R16 is a safe swap for 225/75R15 by the usual ±3% rule: the diameter differs by +0.40%.
What's the difference between 225/75R15 and 225/70R16?
225/70R16 is 0.11" taller and 0 mm wider; the sidewall is -0.44". At an indicated 60 mph you'd actually be doing 60.2 mph.
Will 225/70R16 fit on 225/75R15 wheels?
No — 225/75R15 needs a 15" wheel and 225/70R16 a 16" wheel. This is a plus/minus-size swap that changes wheels too.