TireSizesFinder

185/55R15 vs 175/60R15

175/60R15 is 0.26 in (6.5 mm) taller than 185/55R15, a +1.11% diameter difference. With the speedometer set for 185/55R15, an indicated 60 mph is 60.7 mph on 175/60R15.

Is this a safe swap?

Diameter difference +1.11%: within the ±3% guideline

By overall diameter alone, 175/60R15 falls inside the ±3% range commonly used as a guideline when replacing 185/55R15. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 185/55R15 (23.01 in) vs 175/60R15 (23.27 in)185/55R1523.01 in × 7.28 in175/60R1523.27 in × 6.89 in
Side profile and tread width, drawn to the same scale.
185/55R15 vs 175/60R15 differences
Measurement185/55R15175/60R15Difference% diff
Overall diameter23.01 in (584.5 mm)23.27 in (591.0 mm)+0.26 in (+6.5 mm)+1.11%
Sidewall height4.01 in (101.8 mm)4.13 in (105.0 mm)+0.13 in (+3.3 mm)+3.19%
Section width7.28 in (185.0 mm)6.89 in (175.0 mm)−0.39 in (−10.0 mm)−5.41%
Circumference72.29 in (1,836.3 mm)73.10 in (1,856.7 mm)+0.80 in (+20.4 mm)+1.11%
Revolutions per mile876867−10−1.10%
True speed with the speedometer calibrated for 185/55R15
IndicatedActual on 185/55R15Actual on 175/60R15Difference
30 mph30.0 mph30.3 mph+0.3 mph
60 mph60.0 mph60.7 mph+0.7 mph
75 mph75.0 mph75.8 mph+0.8 mph

Ride-height change: 175/60R15 raises the vehicle by 0.13 in (3.3 mm) at the axle (half the +6.5 mm diameter difference).

175/60R15 is 0.26 in taller than 185/55R15 and 10 mm narrower, a 1.11% difference in overall diameter.

With the speedometer calibrated for 185/55R15, an indicated 60 mph is actually 60.7 mph on 175/60R15, and revolutions per mile change from 876 to 867.

Both sizes mount on 15-inch wheels.

Size pages

Other comparisons with 185/55R15

Other comparisons with 175/60R15

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