355/35R19 vs 345/35R19
Going from one to the other changes the overall height by -1.0 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 355/35R19 | 345/35R19 | Change |
|---|---|---|---|
| Overall height | 28.8" | 28.5" | -1.0 % |
| Sidewall | 4.89" | 4.75" | -2.8 % |
| Section width | 355 mm | 345 mm | -2.8 % |
| Circumference | 90.4" | 89.6" | -1.0 % |
| Revs per mile | 701 | 707 | +1.0 % |
| Axle height | 14.39" | 14.25" | -3.5 mm |
| Approved rim width | 10–13" | 9.5–12.5" | overlap 10–12.5" |
Both are approved on a rim 10" to 12.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 355/35R19. Fit 345/35R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.5 mph | -0.5 |
| 70 mph | 69.3 mph | -0.7 |
| 90 mph | 89.1 mph | -0.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,904 on the road, so it over-counts by 96. At a true 70 mph the first turns 817 times a minute, the second 825.