295/55R19 vs 315/55R19
Going from one to the other changes the overall height by +2.7 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 295/55R19 | 315/55R19 | Change |
|---|---|---|---|
| Overall height | 31.8" | 32.6" | +2.7 % |
| Sidewall | 6.39" | 6.82" | +6.8 % |
| Section width | 295 mm | 315 mm | +6.8 % |
| Circumference | 99.8" | 102.5" | +2.7 % |
| Revs per mile | 635 | 618 | -2.7 % |
| Axle height | 15.89" | 16.32" | +11.0 mm |
| Approved rim width | 8.5–11" | 8.5–11.5" | overlap 8.5–11" |
Both are approved on a rim 8.5" to 11" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 295/55R19. Fit 315/55R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.8 mph | +0.8 |
| 50 mph | 51.4 mph | +1.4 |
| 70 mph | 71.9 mph | +1.9 |
| 90 mph | 92.5 mph | +2.5 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,273 on the road, so it under-counts by 273. At a true 70 mph the first turns 740 times a minute, the second 721.