TireSizesFinder

175/70R13 vs 175/55R15

175/55R15 is 0.07 in (1.7 mm) shorter than 175/70R13, a −0.30% diameter difference. With the speedometer set for 175/70R13, an indicated 60 mph is 59.8 mph on 175/55R15.

Is this a safe swap?

Diameter difference −0.30%: under 1%

By overall diameter alone, 175/55R15 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.

To-scale drawing: 175/70R13 (22.65 in) vs 175/55R15 (22.58 in)175/70R1322.65 in × 6.89 in175/55R1522.58 in × 6.89 in
Side profile and tread width, drawn to the same scale.
175/70R13 vs 175/55R15 differences
Measurement175/70R13175/55R15Difference% diff
Overall diameter22.65 in (575.2 mm)22.58 in (573.5 mm)−0.07 in (−1.7 mm)−0.30%
Sidewall height4.82 in (122.5 mm)3.79 in (96.3 mm)−1.03 in (−26.2 mm)−21.43%
Section width6.89 in (175.0 mm)6.89 in (175.0 mm)0.00 in (0.0 mm)0.00%
Circumference71.14 in (1,807.0 mm)70.93 in (1,801.7 mm)−0.21 in (−5.3 mm)−0.30%
Revolutions per mile891893+3+0.30%
True speed with the speedometer calibrated for 175/70R13
IndicatedActual on 175/70R13Actual on 175/55R15Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.8 mph−0.2 mph
75 mph75.0 mph74.8 mph−0.2 mph

Ride-height change: 175/55R15 lowers the vehicle by 0.03 in (0.9 mm) at the axle (half the −1.7 mm diameter difference).

175/55R15 is 0.07 in shorter than 175/70R13 and the same width, a 0.30% difference in overall diameter.

With the speedometer calibrated for 175/70R13, an indicated 60 mph is actually 59.8 mph on 175/55R15, and revolutions per mile change from 891 to 893.

175/55R15 mounts on a 15-inch wheel, a plus-2 fitment from the 13-inch wheel of 175/70R13.

Size pages

Other comparisons with 175/70R13

Other comparisons with 175/55R15

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