295/50R19 vs 285/55R19
Going from one to the other changes the overall height by +2.4 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 295/50R19 | 285/55R19 | Change |
|---|---|---|---|
| Overall height | 30.6" | 31.3" | +2.4 % |
| Sidewall | 5.81" | 6.17" | +6.3 % |
| Section width | 295 mm | 285 mm | -3.4 % |
| Circumference | 96.2" | 98.5" | +2.4 % |
| Revs per mile | 659 | 643 | -2.4 % |
| Axle height | 15.31" | 15.67" | +9.3 mm |
| Approved rim width | 8.5–11" | 8–10.5" | overlap 8.5–10.5" |
Both are approved on a rim 8.5" to 10.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 295/50R19. Fit 285/55R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.2 mph | +1.2 |
| 70 mph | 71.7 mph | +1.7 |
| 90 mph | 92.1 mph | +2.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,238 on the road, so it under-counts by 238. At a true 70 mph the first turns 769 times a minute, the second 751.