275/60R23 vs 295/55R23
Going from one to the other changes the overall height by -0.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 275/60R23 | 295/55R23 | Change |
|---|---|---|---|
| Overall height | 36.0" | 35.8" | -0.6 % |
| Sidewall | 6.50" | 6.39" | -1.7 % |
| Section width | 275 mm | 295 mm | +7.3 % |
| Circumference | 113.1" | 112.4" | -0.6 % |
| Revs per mile | 560 | 564 | +0.6 % |
| Axle height | 18.00" | 17.89" | -2.8 mm |
| Approved rim width | 7.5–10" | 8.5–11" | overlap 8.5–10" |
Both are approved on a rim 8.5" to 10" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 275/60R23. Fit 295/55R23 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.8 mph | -0.2 |
| 50 mph | 49.7 mph | -0.3 |
| 70 mph | 69.6 mph | -0.4 |
| 90 mph | 89.5 mph | -0.5 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,940 on the road, so it over-counts by 60. At a true 70 mph the first turns 654 times a minute, the second 658.