195/75R15 vs 215/65R15
Going from one to the other changes the overall height by -1.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/75R15 | 215/65R15 | Change |
|---|---|---|---|
| Overall height | 26.5" | 26.0" | -1.9 % |
| Sidewall | 5.76" | 5.50" | -4.4 % |
| Section width | 195 mm | 215 mm | +10.3 % |
| Circumference | 83.3" | 81.7" | -1.9 % |
| Revs per mile | 761 | 776 | +1.9 % |
| Axle height | 13.26" | 13.00" | -6.5 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 195/75R15. Fit 215/65R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.4 mph | -0.6 |
| 50 mph | 49.0 mph | -1.0 |
| 70 mph | 68.6 mph | -1.4 |
| 90 mph | 88.3 mph | -1.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,807 on the road, so it over-counts by 193. At a true 70 mph the first turns 887 times a minute, the second 905.