155/75R14 vs 175/70R14
Going from one to the other changes the overall height by +2.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 155/75R14 | 175/70R14 | Change |
|---|---|---|---|
| Overall height | 23.2" | 23.6" | +2.1 % |
| Sidewall | 4.58" | 4.82" | +5.4 % |
| Section width | 155 mm | 175 mm | +12.9 % |
| Circumference | 72.7" | 74.3" | +2.1 % |
| Revs per mile | 871 | 853 | -2.1 % |
| Axle height | 11.58" | 11.82" | +6.3 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 175/70R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.1 mph | +1.1 |
| 70 mph | 71.5 mph | +1.5 |
| 90 mph | 91.9 mph | +1.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,213 on the road, so it under-counts by 213. At a true 70 mph the first turns 1016 times a minute, the second 995.
What drivers reported
Nobody has filed a complaint naming 155/75R14. 175/70R14 carries 1.