295/40R22 vs 285/45R22
Going from one to the other changes the overall height by +2.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 295/40R22 | 285/45R22 | Change |
|---|---|---|---|
| Overall height | 31.3" | 32.1" | +2.6 % |
| Sidewall | 4.65" | 5.05" | +8.7 % |
| Section width | 295 mm | 285 mm | -3.4 % |
| Circumference | 98.3" | 100.8" | +2.6 % |
| Revs per mile | 645 | 628 | -2.6 % |
| Axle height | 15.65" | 16.05" | +10.3 mm |
| Approved rim width | 8.5–11" | 8–10.5" | overlap 8.5–10.5" |
Both are approved on a rim 8.5" to 10.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 295/40R22. Fit 285/45R22 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.8 mph | +0.8 |
| 50 mph | 51.3 mph | +1.3 |
| 70 mph | 71.8 mph | +1.8 |
| 90 mph | 92.3 mph | +2.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,258 on the road, so it under-counts by 258. At a true 70 mph the first turns 752 times a minute, the second 733.
What drivers reported
Nobody has filed a complaint naming 295/40R22. 285/45R22 carries 6.