265/70R16 vs 275/70R16
Going from one to the other changes the overall height by +1.8 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 265/70R16 | 275/70R16 | Change |
|---|---|---|---|
| Overall height | 30.6" | 31.2" | +1.8 % |
| Sidewall | 7.30" | 7.58" | +3.8 % |
| Section width | 265 mm | 275 mm | +3.8 % |
| Circumference | 96.2" | 97.9" | +1.8 % |
| Revs per mile | 659 | 647 | -1.8 % |
| Axle height | 15.30" | 15.58" | +7.0 mm |
| Approved rim width | 7.5–9.5" | 7.5–10" | 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 265/70R16. Fit 275/70R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.5 mph | +0.5 |
| 50 mph | 50.9 mph | +0.9 |
| 70 mph | 71.3 mph | +1.3 |
| 90 mph | 91.6 mph | +1.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,180 on the road, so it under-counts by 180. At a true 70 mph the first turns 769 times a minute, the second 755.