215/60R15 vs 195/70R15
Going from one to the other changes the overall height by +2.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/60R15 | 195/70R15 | Change |
|---|---|---|---|
| Overall height | 25.2" | 25.7" | +2.3 % |
| Sidewall | 5.08" | 5.37" | +5.8 % |
| Section width | 215 mm | 195 mm | -9.3 % |
| Circumference | 79.0" | 80.9" | +2.3 % |
| Revs per mile | 802 | 783 | -2.3 % |
| Axle height | 12.58" | 12.87" | +7.5 mm |
| Approved rim width | 6–8" | 5.5–7" | 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 215/60R15. Fit 195/70R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.2 mph | +1.2 |
| 70 mph | 71.6 mph | +1.6 |
| 90 mph | 92.1 mph | +2.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,235 on the road, so it under-counts by 235. At a true 70 mph the first turns 935 times a minute, the second 914.