195/80R19 vs 195/75R19
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 | 195/80R19 | 195/75R19 | Change |
|---|---|---|---|
| Overall height | 31.3" | 30.5" | -2.5 % |
| Sidewall | 6.14" | 5.76" | -6.3 % |
| Section width | 195 mm | 195 mm | 0.0 % |
| Circumference | 98.3" | 95.9" | -2.5 % |
| Revs per mile | 645 | 661 | +2.5 % |
| Axle height | 15.64" | 15.26" | -9.8 mm |
| Approved rim width | 5.5–7" | 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 195/80R19. Fit 195/75R19 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 9,755 on the road, so it over-counts by 245. At a true 70 mph the first turns 752 times a minute, the second 771.