185/60R17 vs 175/65R17
Going from one to the other changes the overall height by +0.8 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 185/60R17 | 175/65R17 | Change |
|---|---|---|---|
| Overall height | 25.7" | 26.0" | +0.8 % |
| Sidewall | 4.37" | 4.48" | +2.5 % |
| Section width | 185 mm | 175 mm | -5.4 % |
| Circumference | 80.9" | 81.5" | +0.8 % |
| Revs per mile | 784 | 777 | -0.8 % |
| Axle height | 12.87" | 12.98" | +2.8 mm |
| Approved rim width | 5–6.5" | 5–6" | overlap 5–6" |
Both are approved on a rim 5" to 6" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 185/60R17. Fit 175/65R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.3 mph | +0.3 |
| 50 mph | 50.4 mph | +0.4 |
| 70 mph | 70.6 mph | +0.6 |
| 90 mph | 90.8 mph | +0.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,084 on the road, so it under-counts by 84. At a true 70 mph the first turns 914 times a minute, the second 906.