185/70R13 vs 175/60R15

175/60R15 is 0.07 in (1.8 mm) taller than 185/70R13, a +0.31% diameter difference. With the speedometer set for 185/70R13, an indicated 60 mph is 60.2 mph on 175/60R15.

Is this a safe swap?

Diameter difference +0.31%: under 1%

By overall diameter alone, 175/60R15 is a near match for 185/70R13; 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.

185/70R13 vs 175/60R15 differences
Measurement	185/70R13	175/60R15	Difference	% diff
Overall diameter	23.20 in (589.2 mm)	23.27 in (591.0 mm)	+0.07 in (+1.8 mm)	+0.31%
Sidewall height	5.10 in (129.5 mm)	4.13 in (105.0 mm)	−0.96 in (−24.5 mm)	−18.92%
Section width	7.28 in (185.0 mm)	6.89 in (175.0 mm)	−0.39 in (−10.0 mm)	−5.41%
Circumference	72.88 in (1,851.0 mm)	73.10 in (1,856.7 mm)	+0.22 in (+5.7 mm)	+0.31%
Revolutions per mile	869	867	−3	−0.30%

True speed with the speedometer calibrated for 185/70R13
Indicated	Actual on 185/70R13	Actual on 175/60R15	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.2 mph	+0.2 mph
75 mph	75.0 mph	75.2 mph	+0.2 mph

Ride-height change: 175/60R15 raises the vehicle by 0.04 in (0.9 mm) at the axle (half the +1.8 mm diameter difference).

175/60R15 is 0.07 in taller than 185/70R13 and 10 mm narrower, a 0.31% difference in overall diameter.

With the speedometer calibrated for 185/70R13, an indicated 60 mph is actually 60.2 mph on 175/60R15, and revolutions per mile change from 869 to 867.

175/60R15 mounts on a 15-inch wheel, a plus-2 fitment from the 13-inch wheel of 185/70R13.

Size pages

Other comparisons with 185/70R13

Other comparisons with 175/60R15

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