205/65R15 vs 205/70R15
205/70R15 is outside the ±3% rule as a replacement for 205/65R15: the diameter differs by +3.17%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 205/70R15 on a car calibrated for 205/65R15, the speedometer reads 58.2 mph when you're really doing 60, and the odometer under-counts by 3.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.9 mph |
| 45 mph | 46.4 mph |
| 60 mph | 61.9 mph |
| 70 mph | 72.2 mph |
| 80 mph | 82.5 mph |
Other sizes close to 205/65R15
Questions
Can I replace 205/65R15 with 205/70R15?
205/70R15 is outside the ±3% rule as a replacement for 205/65R15: the diameter differs by +3.17%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 205/65R15 and 205/70R15?
205/70R15 is 0.81" taller and 0 mm wider; the sidewall is +0.40". At an indicated 60 mph you'd actually be doing 61.9 mph.
Will 205/70R15 fit on 205/65R15 wheels?
Both use a 15" rim, so the wheel diameter matches; check the wheel's width range for a 205 mm tire and the fender clearance.