285/60R16 vs 275/65R16
Going from one to the other changes the overall height by +2.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 285/60R16 | 275/65R16 | Change |
|---|---|---|---|
| Overall height | 29.5" | 30.1" | +2.1 % |
| Sidewall | 6.73" | 7.04" | +4.5 % |
| Section width | 285 mm | 275 mm | -3.5 % |
| Circumference | 92.6" | 94.5" | +2.1 % |
| Revs per mile | 684 | 671 | -2.1 % |
| Axle height | 14.73" | 15.04" | +7.8 mm |
| Approved rim width | 8–10.5" | 7.5–10" | 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 285/60R16. Fit 275/65R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.0 mph | +1.0 |
| 70 mph | 71.4 mph | +1.4 |
| 90 mph | 91.9 mph | +1.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,207 on the road, so it under-counts by 207. At a true 70 mph the first turns 799 times a minute, the second 782.