275/65R18 vs 295/60R18
Going from one to the other changes the overall height by -0.4 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 275/65R18 | 295/60R18 | Change |
|---|---|---|---|
| Overall height | 32.1" | 31.9" | -0.4 % |
| Sidewall | 7.04" | 6.97" | -1.0 % |
| Section width | 275 mm | 295 mm | +7.3 % |
| Circumference | 100.8" | 100.3" | -0.4 % |
| Revs per mile | 629 | 631 | +0.4 % |
| Axle height | 16.04" | 15.97" | -1.8 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 275/65R18. Fit 295/60R18 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.9 mph | -0.1 |
| 50 mph | 49.8 mph | -0.2 |
| 70 mph | 69.7 mph | -0.3 |
| 90 mph | 89.6 mph | -0.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,957 on the road, so it over-counts by 43. At a true 70 mph the first turns 734 times a minute, the second 737.
What drivers reported
275/65R18 carries 30 complaints. Nobody has filed one naming 295/60R18.