175/75R17 vs 195/70R17
Going from one to the other changes the overall height by +1.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 175/75R17 | 195/70R17 | Change |
|---|---|---|---|
| Overall height | 27.3" | 27.7" | +1.5 % |
| Sidewall | 5.17" | 5.37" | +4.0 % |
| Section width | 175 mm | 195 mm | +11.4 % |
| Circumference | 85.9" | 87.2" | +1.5 % |
| Revs per mile | 738 | 727 | -1.5 % |
| Axle height | 13.67" | 13.87" | +5.3 mm |
| Approved rim width | 5–6" | 5.5–7" | overlap 5.5–6" |
Both are approved on a rim 5.5" to 6" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 175/75R17. Fit 195/70R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.5 mph | +0.5 |
| 50 mph | 50.8 mph | +0.8 |
| 70 mph | 71.1 mph | +1.1 |
| 90 mph | 91.4 mph | +1.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,151 on the road, so it under-counts by 151. At a true 70 mph the first turns 861 times a minute, the second 848.