265/55R16 vs 285/50R16
Going from one to the other changes the overall height by -0.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 265/55R16 | 285/50R16 | Change |
|---|---|---|---|
| Overall height | 27.5" | 27.2" | -0.9 % |
| Sidewall | 5.74" | 5.61" | -2.2 % |
| Section width | 265 mm | 285 mm | +7.5 % |
| Circumference | 86.3" | 85.5" | -0.9 % |
| Revs per mile | 734 | 741 | +0.9 % |
| Axle height | 13.74" | 13.61" | -3.3 mm |
| Approved rim width | 7.5–9.5" | 8–10.5" | 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 265/55R16. Fit 285/50R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.5 mph | -0.5 |
| 70 mph | 69.3 mph | -0.7 |
| 90 mph | 89.2 mph | -0.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,907 on the road, so it over-counts by 93. At a true 70 mph the first turns 856 times a minute, the second 864.
What drivers reported
265/55R16 carries 2 complaints. Nobody has filed one naming 285/50R16.