295/45R16 vs 305/45R16
Going from one to the other changes the overall height by +1.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 295/45R16 | 305/45R16 | Change |
|---|---|---|---|
| Overall height | 26.5" | 26.8" | +1.3 % |
| Sidewall | 5.23" | 5.40" | +3.4 % |
| Section width | 295 mm | 305 mm | +3.4 % |
| Circumference | 83.1" | 84.2" | +1.3 % |
| Revs per mile | 762 | 752 | -1.3 % |
| Axle height | 13.23" | 13.40" | +4.5 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 295/45R16. Fit 305/45R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.4 mph | +0.4 |
| 50 mph | 50.7 mph | +0.7 |
| 70 mph | 70.9 mph | +0.9 |
| 90 mph | 91.2 mph | +1.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,134 on the road, so it under-counts by 134. At a true 70 mph the first turns 889 times a minute, the second 878.