155/75R14 vs 175/65R14
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 | 155/75R14 | 175/65R14 | Change |
|---|---|---|---|
| Overall height | 23.2" | 23.0" | -0.9 % |
| Sidewall | 4.58" | 4.48" | -2.2 % |
| Section width | 155 mm | 175 mm | +12.9 % |
| Circumference | 72.7" | 72.1" | -0.9 % |
| Revs per mile | 871 | 879 | +0.9 % |
| Axle height | 11.58" | 11.48" | -2.5 mm |
| Approved rim width | 4–5.5" | 5–6" | overlap 5–5.5" |
Both are approved on a rim 5" to 5.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 155/75R14. Fit 175/65R14 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 9,915 on the road, so it over-counts by 85. At a true 70 mph the first turns 1016 times a minute, the second 1025.
What drivers reported
Nobody has filed a complaint naming 155/75R14. 175/65R14 carries 49.