245/50R17 vs 265/45R17
Going from one to the other changes the overall height by -1.0 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 245/50R17 | 265/45R17 | Change |
|---|---|---|---|
| Overall height | 26.6" | 26.4" | -1.0 % |
| Sidewall | 4.82" | 4.69" | -2.7 % |
| Section width | 245 mm | 265 mm | +8.2 % |
| Circumference | 83.7" | 82.9" | -1.0 % |
| Revs per mile | 757 | 764 | +1.0 % |
| Axle height | 13.32" | 13.19" | -3.3 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 245/50R17. Fit 265/45R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.5 mph | -0.5 |
| 70 mph | 69.3 mph | -0.7 |
| 90 mph | 89.1 mph | -0.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,904 on the road, so it over-counts by 96. At a true 70 mph the first turns 883 times a minute, the second 892.
What drivers reported
245/50R17 carries 1 complaints. Nobody has filed one naming 265/45R17.