295/35R17 vs 275/35R17
Going from one to the other changes the overall height by -2.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 295/35R17 | 275/35R17 | Change |
|---|---|---|---|
| Overall height | 25.1" | 24.6" | -2.2 % |
| Sidewall | 4.06" | 3.79" | -6.8 % |
| Section width | 295 mm | 275 mm | -6.8 % |
| Circumference | 78.9" | 77.2" | -2.2 % |
| Revs per mile | 803 | 821 | +2.2 % |
| Axle height | 12.56" | 12.29" | -7.0 mm |
| Approved rim width | 8.5–11" | 7.5–10" | 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 295/35R17. Fit 275/35R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.9 mph | -1.1 |
| 70 mph | 68.5 mph | -1.5 |
| 90 mph | 88.0 mph | -2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,781 on the road, so it over-counts by 219. At a true 70 mph the first turns 936 times a minute, the second 957.