175/70R13 vs 155/80R13

155/80R13 is 0.12 in (3.0 mm) taller than 175/70R13, a +0.52% diameter difference. With the speedometer set for 175/70R13, an indicated 60 mph is 60.3 mph on 155/80R13.

Is this a safe swap?

Diameter difference +0.52%: under 1%

By overall diameter alone, 155/80R13 is a near match for 175/70R13; 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.

175/70R13 vs 155/80R13 differences
Measurement	175/70R13	155/80R13	Difference	% diff
Overall diameter	22.65 in (575.2 mm)	22.76 in (578.2 mm)	+0.12 in (+3.0 mm)	+0.52%
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	71.14 in (1,807.0 mm)	71.51 in (1,816.5 mm)	+0.37 in (+9.4 mm)	+0.52%
Revolutions per mile	891	886	−5	−0.52%

True speed with the speedometer calibrated for 175/70R13
Indicated	Actual on 175/70R13	Actual on 155/80R13	Difference
30 mph	30.0 mph	30.2 mph	+0.2 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: 155/80R13 raises the vehicle by 0.06 in (1.5 mm) at the axle (half the +3.0 mm diameter difference).

155/80R13 is 0.12 in taller than 175/70R13 and 20 mm narrower, a 0.52% difference in overall diameter.

With the speedometer calibrated for 175/70R13, an indicated 60 mph is actually 60.3 mph on 155/80R13, and revolutions per mile change from 891 to 886.

Both sizes mount on 13-inch wheels.

Size pages

Other comparisons with 175/70R13

Other comparisons with 155/80R13

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