205/50R15 vs 175/65R15
175/65R15 is outside the ±3% rule as a replacement for 205/50R15: the diameter differs by +3.84%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 175/65R15 on a car calibrated for 205/50R15, the speedometer reads 57.8 mph when you're really doing 60, and the odometer under-counts by 3.8%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.2 mph |
| 45 mph | 46.7 mph |
| 60 mph | 62.3 mph |
| 70 mph | 72.7 mph |
| 80 mph | 83.1 mph |
Other sizes close to 205/50R15
- 205/50R15 vs 185/60R15+2.90%
- 205/50R15 vs 195/60R15+4.95%
- 205/50R15 vs 185/55R15-0.26%
- 205/50R15 vs 195/55R15+1.62%
- 205/50R15 vs 205/45R16+0.84%
- 205/50R15 vs 175/65R14-0.49%
- 205/50R15 vs 225/45R15-0.43%
- 205/50R15 vs 195/50R15-1.71%
- 205/50R15 vs 225/50R15+3.41%
- 205/50R15 vs 195/60R14+0.61%
- 205/50R15 vs 245/40R15-1.54%
Questions
Can I replace 205/50R15 with 175/65R15?
175/65R15 is outside the ±3% rule as a replacement for 205/50R15: the diameter differs by +3.84%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 205/50R15 and 175/65R15?
175/65R15 is 0.89" taller and 30 mm narrower; the sidewall is +0.44". At an indicated 60 mph you'd actually be doing 62.3 mph.
Will 175/65R15 fit on 205/50R15 wheels?
Both use a 15" rim, so the wheel diameter matches; check the wheel's width range for a 175 mm tire and the fender clearance.