215/80R19 vs 225/75R19
Going from one to the other changes the overall height by -0.8 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/80R19 | 225/75R19 | Change |
|---|---|---|---|
| Overall height | 32.5" | 32.3" | -0.8 % |
| Sidewall | 6.77" | 6.64" | -1.9 % |
| Section width | 215 mm | 225 mm | +4.7 % |
| Circumference | 102.2" | 101.4" | -0.8 % |
| Revs per mile | 620 | 625 | +0.8 % |
| Axle height | 16.27" | 16.14" | -3.3 mm |
| Approved rim width | 6–8" | 6–8.5" | 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 215/80R19. Fit 225/75R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.8 mph | -0.2 |
| 50 mph | 49.6 mph | -0.4 |
| 70 mph | 69.4 mph | -0.6 |
| 90 mph | 89.3 mph | -0.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,921 on the road, so it over-counts by 79. At a true 70 mph the first turns 723 times a minute, the second 729.