TireSizesFinder

155/80R13 vs 175/55R15

175/55R15 is 0.19 in (4.7 mm) shorter than 155/80R13, a −0.81% diameter difference. With the speedometer set for 155/80R13, an indicated 60 mph is 59.5 mph on 175/55R15.

Is this a safe swap?

Diameter difference −0.81%: under 1%

By overall diameter alone, 175/55R15 is a near match for 155/80R13; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 155/80R13 (22.76 in) vs 175/55R15 (22.58 in)155/80R1322.76 in × 6.10 in175/55R1522.58 in × 6.89 in
Side profile and tread width, drawn to the same scale.
155/80R13 vs 175/55R15 differences
Measurement155/80R13175/55R15Difference% diff
Overall diameter22.76 in (578.2 mm)22.58 in (573.5 mm)−0.19 in (−4.7 mm)−0.81%
Sidewall height4.88 in (124.0 mm)3.79 in (96.3 mm)−1.09 in (−27.7 mm)−22.38%
Section width6.10 in (155.0 mm)6.89 in (175.0 mm)+0.79 in (+20.0 mm)+12.90%
Circumference71.51 in (1,816.5 mm)70.93 in (1,801.7 mm)−0.58 in (−14.8 mm)−0.81%
Revolutions per mile886893+7+0.82%
True speed with the speedometer calibrated for 155/80R13
IndicatedActual on 155/80R13Actual on 175/55R15Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 175/55R15 lowers the vehicle by 0.09 in (2.4 mm) at the axle (half the −4.7 mm diameter difference).

175/55R15 is 0.19 in shorter than 155/80R13 and 20 mm wider, a 0.81% difference in overall diameter.

With the speedometer calibrated for 155/80R13, an indicated 60 mph is actually 59.5 mph on 175/55R15, and revolutions per mile change from 886 to 893.

175/55R15 mounts on a 15-inch wheel, a plus-2 fitment from the 13-inch wheel of 155/80R13.

Size pages

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Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.