205/45R20 vs 225/45R20
Going from one to the other changes the overall height by +2.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 205/45R20 | 225/45R20 | Change |
|---|---|---|---|
| Overall height | 27.3" | 28.0" | +2.6 % |
| Sidewall | 3.63" | 3.99" | +9.8 % |
| Section width | 205 mm | 225 mm | +9.8 % |
| Circumference | 85.7" | 87.9" | +2.6 % |
| Revs per mile | 740 | 721 | -2.6 % |
| Axle height | 13.63" | 13.99" | +9.0 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 205/45R20. Fit 225/45R20 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.8 mph | +0.8 |
| 50 mph | 51.3 mph | +1.3 |
| 70 mph | 71.8 mph | +1.8 |
| 90 mph | 92.3 mph | +2.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,260 on the road, so it under-counts by 260. At a true 70 mph the first turns 863 times a minute, the second 841.
What drivers reported
Nobody has filed a complaint naming 205/45R20. 225/45R20 carries 1.