255/50R15 vs 265/45R15
Going from one to the other changes the overall height by -2.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 255/50R15 | 265/45R15 | Change |
|---|---|---|---|
| Overall height | 25.0" | 24.4" | -2.6 % |
| Sidewall | 5.02" | 4.69" | -6.5 % |
| Section width | 255 mm | 265 mm | +3.9 % |
| Circumference | 78.7" | 76.6" | -2.6 % |
| Revs per mile | 805 | 827 | +2.6 % |
| Axle height | 12.52" | 12.19" | -8.3 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 255/50R15. Fit 265/45R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.2 mph | -0.8 |
| 50 mph | 48.7 mph | -1.3 |
| 70 mph | 68.2 mph | -1.8 |
| 90 mph | 87.7 mph | -2.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,741 on the road, so it over-counts by 259. At a true 70 mph the first turns 940 times a minute, the second 965.
What drivers reported
Nobody has filed a complaint naming 255/50R15. 265/45R15 carries 1.