265/75R16 vs 245/85R16
Going from one to the other changes the overall height by +2.4 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 265/75R16 | 245/85R16 | Change |
|---|---|---|---|
| Overall height | 31.6" | 32.4" | +2.4 % |
| Sidewall | 7.82" | 8.20" | +4.8 % |
| Section width | 265 mm | 245 mm | -7.5 % |
| Circumference | 99.4" | 101.8" | +2.4 % |
| Revs per mile | 637 | 623 | -2.4 % |
| Axle height | 15.82" | 16.20" | +9.5 mm |
| Approved rim width | 7.5–9.5" | 7–9" | 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 265/75R16. Fit 245/85R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.2 mph | +1.2 |
| 70 mph | 71.7 mph | +1.7 |
| 90 mph | 92.1 mph | +2.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,236 on the road, so it under-counts by 236. At a true 70 mph the first turns 743 times a minute, the second 726.
What drivers reported
265/75R16 carries 253 complaints and 1 deaths. Nobody has filed one naming 245/85R16.