205/65R15 vs 225/55R15
Going from one to the other changes the overall height by -2.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 205/65R15 | 225/55R15 | Change |
|---|---|---|---|
| Overall height | 25.5" | 24.7" | -2.9 % |
| Sidewall | 5.25" | 4.87" | -7.1 % |
| Section width | 205 mm | 225 mm | +9.8 % |
| Circumference | 80.1" | 77.7" | -2.9 % |
| Revs per mile | 791 | 815 | +2.9 % |
| Axle height | 12.75" | 12.37" | -9.5 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 205/65R15. Fit 225/55R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.1 mph | -0.9 |
| 50 mph | 48.5 mph | -1.5 |
| 70 mph | 67.9 mph | -2.1 |
| 90 mph | 87.4 mph | -2.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,707 on the road, so it over-counts by 293. At a true 70 mph the first turns 923 times a minute, the second 951.
What drivers reported
205/65R15 carries 182 complaints. Nobody has filed one naming 225/55R15.