325/65R22 vs 345/60R22
Going from one to the other changes the overall height by -0.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 325/65R22 | 345/60R22 | Change |
|---|---|---|---|
| Overall height | 38.6" | 38.3" | -0.9 % |
| Sidewall | 8.32" | 8.15" | -2.0 % |
| Section width | 325 mm | 345 mm | +6.2 % |
| Circumference | 121.4" | 120.3" | -0.9 % |
| Revs per mile | 522 | 527 | +0.9 % |
| Axle height | 19.32" | 19.15" | -4.3 mm |
| Approved rim width | 9–12" | 9.5–12.5" | overlap 9.5–12" |
Both are approved on a rim 9.5" to 12" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 325/65R22. Fit 345/60R22 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.6 mph | -0.4 |
| 70 mph | 69.4 mph | -0.6 |
| 90 mph | 89.2 mph | -0.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,913 on the road, so it over-counts by 87. At a true 70 mph the first turns 609 times a minute, the second 614.