285/60R19 vs 265/60R19
Going from one to the other changes the overall height by -2.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 285/60R19 | 265/60R19 | Change |
|---|---|---|---|
| Overall height | 32.5" | 31.5" | -2.9 % |
| Sidewall | 6.73" | 6.26" | -7.0 % |
| Section width | 285 mm | 265 mm | -7.0 % |
| Circumference | 102.0" | 99.0" | -2.9 % |
| Revs per mile | 621 | 640 | +2.9 % |
| Axle height | 16.23" | 15.76" | -12.0 mm |
| Approved rim width | 8–10.5" | 7.5–9.5" | overlap 8–9.5" |
Both are approved on a rim 8" to 9.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 285/60R19. Fit 265/60R19 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 | 68.0 mph | -2.0 |
| 90 mph | 87.4 mph | -2.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,709 on the road, so it over-counts by 291. At a true 70 mph the first turns 725 times a minute, the second 747.