205/50R19 vs 195/50R19
Going from one to the other changes the overall height by -1.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 205/50R19 | 195/50R19 | Change |
|---|---|---|---|
| Overall height | 27.1" | 26.7" | -1.5 % |
| Sidewall | 4.04" | 3.84" | -4.9 % |
| Section width | 205 mm | 195 mm | -4.9 % |
| Circumference | 85.0" | 83.8" | -1.5 % |
| Revs per mile | 745 | 756 | +1.5 % |
| Axle height | 13.54" | 13.34" | -5.0 mm |
| Approved rim width | 5.5–7.5" | 5.5–7" | overlap 5.5–7" |
Both are approved on a rim 5.5" to 7" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 205/50R19. Fit 195/50R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.3 mph | -0.7 |
| 70 mph | 69.0 mph | -1.0 |
| 90 mph | 88.7 mph | -1.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,855 on the road, so it over-counts by 145. At a true 70 mph the first turns 869 times a minute, the second 882.