315/55R17 vs 335/50R17
Going from one to the other changes the overall height by -1.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 315/55R17 | 335/50R17 | Change |
|---|---|---|---|
| Overall height | 30.6" | 30.2" | -1.5 % |
| Sidewall | 6.82" | 6.59" | -3.3 % |
| Section width | 315 mm | 335 mm | +6.3 % |
| Circumference | 96.3" | 94.8" | -1.5 % |
| Revs per mile | 658 | 668 | +1.5 % |
| Axle height | 15.32" | 15.09" | -5.8 mm |
| Approved rim width | 8.5–11.5" | 9.5–12.5" | overlap 9.5–11.5" |
Both are approved on a rim 9.5" to 11.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 315/55R17. Fit 335/50R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.3 mph | -0.7 |
| 70 mph | 69.0 mph | -1.0 |
| 90 mph | 88.7 mph | -1.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,852 on the road, so it over-counts by 148. At a true 70 mph the first turns 768 times a minute, the second 779.