205/75R15 vs 225/65R15
Going from one to the other changes the overall height by -2.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 205/75R15 | 225/65R15 | Change |
|---|---|---|---|
| Overall height | 27.1" | 26.5" | -2.2 % |
| Sidewall | 6.05" | 5.76" | -4.9 % |
| Section width | 205 mm | 225 mm | +9.8 % |
| Circumference | 85.2" | 83.3" | -2.2 % |
| Revs per mile | 744 | 761 | +2.2 % |
| Axle height | 13.55" | 13.26" | -7.5 mm |
| Approved rim width | 5.5–7.5" | 6–8.5" | overlap 6–7.5" |
Both are approved on a rim 6" to 7.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 205/75R15. Fit 225/65R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.9 mph | -1.1 |
| 70 mph | 68.5 mph | -1.5 |
| 90 mph | 88.0 mph | -2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,782 on the road, so it over-counts by 218. At a true 70 mph the first turns 868 times a minute, the second 887.
What drivers reported
205/75R15 carries 84 complaints. Nobody has filed one naming 225/65R15.