195/55R14 vs 215/50R14
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 | 195/55R14 | 215/50R14 | Change |
|---|---|---|---|
| Overall height | 22.4" | 22.5" | +0.1 % |
| Sidewall | 4.22" | 4.23" | +0.2 % |
| Section width | 195 mm | 215 mm | +10.3 % |
| Circumference | 70.5" | 70.6" | +0.1 % |
| Revs per mile | 899 | 898 | -0.1 % |
| Axle height | 11.22" | 11.23" | +0.3 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 195/55R14. Fit 215/50R14 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 | 70.1 mph | +0.1 |
| 90 mph | 90.1 mph | +0.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,009 on the road, so it under-counts by 9. At a true 70 mph the first turns 1048 times a minute, the second 1047.