305/55R24 vs 295/60R24
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 | 305/55R24 | 295/60R24 | Change |
|---|---|---|---|
| Overall height | 37.2" | 37.9" | +2.0 % |
| Sidewall | 6.60" | 6.97" | +5.5 % |
| Section width | 305 mm | 295 mm | -3.3 % |
| Circumference | 116.9" | 119.2" | +2.0 % |
| Revs per mile | 542 | 532 | -2.0 % |
| Axle height | 18.60" | 18.97" | +9.3 mm |
| Approved rim width | 8.5–11" | 8.5–11" | overlap 8.5–11" |
Both are approved on a rim 8.5" to 11" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 305/55R24. Fit 295/60R24 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.0 mph | +1.0 |
| 70 mph | 71.4 mph | +1.4 |
| 90 mph | 91.8 mph | +1.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,196 on the road, so it under-counts by 196. At a true 70 mph the first turns 632 times a minute, the second 620.