245/85R17 vs 265/75R17
Going from one to the other changes the overall height by -2.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 245/85R17 | 265/75R17 | Change |
|---|---|---|---|
| Overall height | 33.4" | 32.6" | -2.2 % |
| Sidewall | 8.20" | 7.82" | -4.6 % |
| Section width | 245 mm | 265 mm | +8.2 % |
| Circumference | 104.9" | 102.6" | -2.2 % |
| Revs per mile | 604 | 618 | +2.2 % |
| Axle height | 16.70" | 16.32" | -9.5 mm |
| Approved rim width | 7–9" | 7.5–9.5" | overlap 7.5–9" |
Both are approved on a rim 7.5" to 9" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 245/85R17. Fit 265/75R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.9 mph | -1.1 |
| 70 mph | 68.4 mph | -1.6 |
| 90 mph | 88.0 mph | -2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,776 on the road, so it over-counts by 224. At a true 70 mph the first turns 705 times a minute, the second 721.
What drivers reported
Nobody has filed a complaint naming 245/85R17. 265/75R17 carries 5.