215/50R16 vs 195/55R16
Going from one to the other changes the overall height by -0.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/50R16 | 195/55R16 | Change |
|---|---|---|---|
| Overall height | 24.5" | 24.4" | -0.1 % |
| Sidewall | 4.23" | 4.22" | -0.2 % |
| Section width | 215 mm | 195 mm | -9.3 % |
| Circumference | 76.9" | 76.8" | -0.1 % |
| Revs per mile | 824 | 825 | +0.1 % |
| Axle height | 12.23" | 12.22" | -0.3 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 215/50R16. Fit 195/55R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.0 mph | -0.0 |
| 50 mph | 50.0 mph | -0.0 |
| 70 mph | 69.9 mph | -0.1 |
| 90 mph | 89.9 mph | -0.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,992 on the road, so it over-counts by 8. At a true 70 mph the first turns 962 times a minute, the second 963.