195/65R17 vs 215/55R17
Going from one to the other changes the overall height by -2.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/65R17 | 215/55R17 | Change |
|---|---|---|---|
| Overall height | 27.0" | 26.3" | -2.5 % |
| Sidewall | 4.99" | 4.66" | -6.7 % |
| Section width | 195 mm | 215 mm | +10.3 % |
| Circumference | 84.8" | 82.7" | -2.5 % |
| Revs per mile | 748 | 767 | +2.5 % |
| Axle height | 13.49" | 13.16" | -8.5 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 195/65R17. Fit 215/55R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.8 mph | -1.2 |
| 70 mph | 68.3 mph | -1.7 |
| 90 mph | 87.8 mph | -2.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,752 on the road, so it over-counts by 248. At a true 70 mph the first turns 872 times a minute, the second 894.