155/80R14 vs 175/70R14
Going from one to the other changes the overall height by -0.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 155/80R14 | 175/70R14 | Change |
|---|---|---|---|
| Overall height | 23.8" | 23.6" | -0.5 % |
| Sidewall | 4.88" | 4.82" | -1.2 % |
| Section width | 155 mm | 175 mm | +12.9 % |
| Circumference | 74.7" | 74.3" | -0.5 % |
| Revs per mile | 849 | 853 | +0.5 % |
| Axle height | 11.88" | 11.82" | -1.5 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 155/80R14. Fit 175/70R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.9 mph | -0.1 |
| 50 mph | 49.8 mph | -0.2 |
| 70 mph | 69.7 mph | -0.3 |
| 90 mph | 89.6 mph | -0.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,950 on the road, so it over-counts by 50. At a true 70 mph the first turns 990 times a minute, the second 995.
What drivers reported
Nobody has filed a complaint naming 155/80R14. 175/70R14 carries 1.