275/40R18 vs 295/35R18
Going from one to the other changes the overall height by -2.0 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 275/40R18 | 295/35R18 | Change |
|---|---|---|---|
| Overall height | 26.7" | 26.1" | -2.0 % |
| Sidewall | 4.33" | 4.06" | -6.1 % |
| Section width | 275 mm | 295 mm | +7.3 % |
| Circumference | 83.8" | 82.1" | -2.0 % |
| Revs per mile | 756 | 772 | +2.0 % |
| Axle height | 13.33" | 13.06" | -6.8 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 275/40R18. Fit 295/35R18 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.4 mph | -0.6 |
| 50 mph | 49.0 mph | -1.0 |
| 70 mph | 68.6 mph | -1.4 |
| 90 mph | 88.2 mph | -1.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,801 on the road, so it over-counts by 199. At a true 70 mph the first turns 883 times a minute, the second 900.
What drivers reported
275/40R18 carries 2 complaints. Nobody has filed one naming 295/35R18.