175/70R14 vs 155/80R14

155/80R14 is 0.12 in (3.0 mm) taller than 175/70R14, a +0.50% diameter difference. With the speedometer set for 175/70R14, an indicated 60 mph is 60.3 mph on 155/80R14.

Is this a safe swap?

Diameter difference +0.50%: under 1%

By overall diameter alone, 155/80R14 is a near match for 175/70R14; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

175/70R14 vs 155/80R14 differences
Measurement	175/70R14	155/80R14	Difference	% diff
Overall diameter	23.65 in (600.6 mm)	23.76 in (603.6 mm)	+0.12 in (+3.0 mm)	+0.50%
Sidewall height	4.82 in (122.5 mm)	4.88 in (124.0 mm)	+0.06 in (+1.5 mm)	+1.22%
Section width	6.89 in (175.0 mm)	6.10 in (155.0 mm)	−0.79 in (−20.0 mm)	−11.43%
Circumference	74.29 in (1,886.8 mm)	74.66 in (1,896.3 mm)	+0.37 in (+9.4 mm)	+0.50%
Revolutions per mile	853	849	−4	−0.50%

True speed with the speedometer calibrated for 175/70R14
Indicated	Actual on 175/70R14	Actual on 155/80R14	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.4 mph	+0.4 mph

Ride-height change: 155/80R14 raises the vehicle by 0.06 in (1.5 mm) at the axle (half the +3.0 mm diameter difference).

155/80R14 is 0.12 in taller than 175/70R14 and 20 mm narrower, a 0.50% difference in overall diameter.

With the speedometer calibrated for 175/70R14, an indicated 60 mph is actually 60.3 mph on 155/80R14, and revolutions per mile change from 853 to 849.

Both sizes mount on 14-inch wheels.

Size pages

Other comparisons with 175/70R14

Other comparisons with 155/80R14

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.