215/55R19 vs 215/50R19
Going from one to the other changes the overall height by -3.0 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/55R19 | 215/50R19 | Change |
|---|---|---|---|
| Overall height | 28.3" | 27.5" | -3.0 % |
| Sidewall | 4.66" | 4.23" | -9.1 % |
| Section width | 215 mm | 215 mm | 0.0 % |
| Circumference | 88.9" | 86.3" | -3.0 % |
| Revs per mile | 712 | 734 | +3.0 % |
| Axle height | 14.16" | 13.73" | -10.8 mm |
| Approved rim width | 6–8" | 6–8" | overlap 6–8" |
Both are approved on a rim 6" to 8" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 215/55R19. Fit 215/50R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.1 mph | -0.9 |
| 50 mph | 48.5 mph | -1.5 |
| 70 mph | 67.9 mph | -2.1 |
| 90 mph | 87.3 mph | -2.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,701 on the road, so it over-counts by 299. At a true 70 mph the first turns 831 times a minute, the second 857.