255/65R20 vs 265/60R20
Going from one to the other changes the overall height by -1.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 255/65R20 | 265/60R20 | Change |
|---|---|---|---|
| Overall height | 33.1" | 32.5" | -1.6 % |
| Sidewall | 6.53" | 6.26" | -4.1 % |
| Section width | 255 mm | 265 mm | +3.9 % |
| Circumference | 103.8" | 102.2" | -1.6 % |
| Revs per mile | 610 | 620 | +1.6 % |
| Axle height | 16.53" | 16.26" | -6.8 mm |
| Approved rim width | 7–9.5" | 7.5–9.5" | overlap 7.5–9.5" |
Both are approved on a rim 7.5" 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 255/65R20. Fit 265/60R20 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.5 mph | -0.5 |
| 50 mph | 49.2 mph | -0.8 |
| 70 mph | 68.9 mph | -1.1 |
| 90 mph | 88.6 mph | -1.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,839 on the road, so it over-counts by 161. At a true 70 mph the first turns 712 times a minute, the second 724.
What drivers reported
Nobody has filed a complaint naming 255/65R20. 265/60R20 carries 2.