175/65R14 vs 175/70R14
175/70R14 is outside the ±3% rule as a replacement for 175/65R14: the diameter differs by +3.00%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 175/70R14 on a car calibrated for 175/65R14, the speedometer reads 58.3 mph when you're really doing 60, and the odometer under-counts by 3.0%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 30.9 mph |
| 45 mph | 46.4 mph |
| 60 mph | 61.8 mph |
| 70 mph | 72.1 mph |
| 80 mph | 82.4 mph |
Other sizes close to 175/65R14
Questions
Can I replace 175/65R14 with 175/70R14?
175/70R14 is outside the ±3% rule as a replacement for 175/65R14: the diameter differs by +3.00%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 175/65R14 and 175/70R14?
175/70R14 is 0.69" taller and 0 mm wider; the sidewall is +0.34". At an indicated 60 mph you'd actually be doing 61.8 mph.
Will 175/70R14 fit on 175/65R14 wheels?
Both use a 14" rim, so the wheel diameter matches; check the wheel's width range for a 175 mm tire and the fender clearance.