195/85R17 vs 215/75R17
Going from one to the other changes the overall height by -1.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/85R17 | 215/75R17 | Change |
|---|---|---|---|
| Overall height | 30.1" | 29.7" | -1.2 % |
| Sidewall | 6.53" | 6.35" | -2.7 % |
| Section width | 195 mm | 215 mm | +10.3 % |
| Circumference | 94.4" | 93.3" | -1.2 % |
| Revs per mile | 671 | 679 | +1.2 % |
| Axle height | 15.03" | 14.85" | -4.5 mm |
| Approved rim width | 5.5–7" | 6–8" | overlap 6–7" |
Both are approved on a rim 6" to 7" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 195/85R17. Fit 215/75R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.4 mph | -0.6 |
| 70 mph | 69.2 mph | -0.8 |
| 90 mph | 88.9 mph | -1.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,882 on the road, so it over-counts by 118. At a true 70 mph the first turns 783 times a minute, the second 792.