225/65R17 vs 205/75R17
Going from one to the other changes the overall height by +2.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 225/65R17 | 205/75R17 | Change |
|---|---|---|---|
| Overall height | 28.5" | 29.1" | +2.1 % |
| Sidewall | 5.76" | 6.05" | +5.1 % |
| Section width | 225 mm | 205 mm | -8.9 % |
| Circumference | 89.6" | 91.4" | +2.1 % |
| Revs per mile | 707 | 693 | -2.1 % |
| Axle height | 14.26" | 14.55" | +7.5 mm |
| Approved rim width | 6–8.5" | 5.5–7.5" | 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 225/65R17. Fit 205/75R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.0 mph | +1.0 |
| 70 mph | 71.4 mph | +1.4 |
| 90 mph | 91.9 mph | +1.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,207 on the road, so it under-counts by 207. At a true 70 mph the first turns 825 times a minute, the second 808.
What drivers reported
225/65R17 carries 60 complaints. Nobody has filed one naming 205/75R17.