275/70R16 vs 285/70R16
Going from one to the other changes the overall height by +1.8 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 275/70R16 | 285/70R16 | Change |
|---|---|---|---|
| Overall height | 31.2" | 31.7" | +1.8 % |
| Sidewall | 7.58" | 7.85" | +3.6 % |
| Section width | 275 mm | 285 mm | +3.6 % |
| Circumference | 97.9" | 99.6" | +1.8 % |
| Revs per mile | 647 | 636 | -1.8 % |
| Axle height | 15.58" | 15.85" | +7.0 mm |
| Approved rim width | 7.5–10" | 8–10.5" | overlap 8–10" |
Both are approved on a rim 8" to 10" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 275/70R16. Fit 285/70R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.5 mph | +0.5 |
| 50 mph | 50.9 mph | +0.9 |
| 70 mph | 71.2 mph | +1.2 |
| 90 mph | 91.6 mph | +1.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,177 on the road, so it under-counts by 177. At a true 70 mph the first turns 755 times a minute, the second 742.
What drivers reported
275/70R16 carries 7 complaints. Nobody has filed one naming 285/70R16.