175/70R14 vs 185/70R14

185/70R14 is 0.55 in (14.0 mm) taller than 175/70R14, a +2.33% diameter difference. With the speedometer set for 175/70R14, an indicated 60 mph is 61.4 mph on 185/70R14.

Is this a safe swap?

Diameter difference +2.33%: within the ±3% guideline

By overall diameter alone, 185/70R14 falls inside the ±3% range commonly used as a guideline when replacing 175/70R14. 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.

175/70R14 vs 185/70R14 differences
Measurement	175/70R14	185/70R14	Difference	% diff
Overall diameter	23.65 in (600.6 mm)	24.20 in (614.6 mm)	+0.55 in (+14.0 mm)	+2.33%
Sidewall height	4.82 in (122.5 mm)	5.10 in (129.5 mm)	+0.28 in (+7.0 mm)	+5.71%
Section width	6.89 in (175.0 mm)	7.28 in (185.0 mm)	+0.39 in (+10.0 mm)	+5.71%
Circumference	74.29 in (1,886.8 mm)	76.02 in (1,930.8 mm)	+1.73 in (+44.0 mm)	+2.33%
Revolutions per mile	853	834	−19	−2.28%

True speed with the speedometer calibrated for 175/70R14
Indicated	Actual on 175/70R14	Actual on 185/70R14	Difference
30 mph	30.0 mph	30.7 mph	+0.7 mph
60 mph	60.0 mph	61.4 mph	+1.4 mph
75 mph	75.0 mph	76.7 mph	+1.7 mph

Ride-height change: 185/70R14 raises the vehicle by 0.28 in (7.0 mm) at the axle (half the +14.0 mm diameter difference).

185/70R14 is 0.55 in taller than 175/70R14 and 10 mm wider, a 2.33% difference in overall diameter.

With the speedometer calibrated for 175/70R14, an indicated 60 mph is actually 61.4 mph on 185/70R14, and revolutions per mile change from 853 to 834.

Both sizes mount on 14-inch wheels.

Size pages

Other comparisons with 175/70R14

Other comparisons with 185/70R14

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