295/25R22 vs 295/30R22
295/30R22 is outside the ±3% rule as a replacement for 295/25R22: the diameter differs by +4.18%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
Speedometer and odometer
With 295/30R22 on a car calibrated for 295/25R22, the speedometer reads 57.6 mph when you're really doing 60, and the odometer under-counts by 4.2%.
| Speedo shows | Actual speed |
|---|---|
| 30 mph | 31.3 mph |
| 45 mph | 46.9 mph |
| 60 mph | 62.5 mph |
| 70 mph | 72.9 mph |
| 80 mph | 83.3 mph |
Other sizes close to 295/25R22
Questions
Can I replace 295/25R22 with 295/30R22?
295/30R22 is outside the ±3% rule as a replacement for 295/25R22: the diameter differs by +4.18%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.
What's the difference between 295/25R22 and 295/30R22?
295/30R22 is 1.16" taller and 0 mm wider; the sidewall is +0.58". At an indicated 60 mph you'd actually be doing 62.5 mph.
Will 295/30R22 fit on 295/25R22 wheels?
Both use a 22" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.