145/80R13 vs 175/70R13

175/70R13 is 0.51 in (13.0 mm) taller than 145/80R13, a +2.31% diameter difference. With the speedometer set for 145/80R13, an indicated 60 mph is 61.4 mph on 175/70R13.

Is this a safe swap?

Diameter difference +2.31%: within the ±3% guideline

By overall diameter alone, 175/70R13 falls inside the ±3% range commonly used as a guideline when replacing 145/80R13. 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.

145/80R13 vs 175/70R13 differences
Measurement	145/80R13	175/70R13	Difference	% diff
Overall diameter	22.13 in (562.2 mm)	22.65 in (575.2 mm)	+0.51 in (+13.0 mm)	+2.31%
Sidewall height	4.57 in (116.0 mm)	4.82 in (122.5 mm)	+0.26 in (+6.5 mm)	+5.60%
Section width	5.71 in (145.0 mm)	6.89 in (175.0 mm)	+1.18 in (+30.0 mm)	+20.69%
Circumference	69.54 in (1,766.2 mm)	71.14 in (1,807.0 mm)	+1.61 in (+40.8 mm)	+2.31%
Revolutions per mile	911	891	−21	−2.26%

True speed with the speedometer calibrated for 145/80R13
Indicated	Actual on 145/80R13	Actual on 175/70R13	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: 175/70R13 raises the vehicle by 0.26 in (6.5 mm) at the axle (half the +13.0 mm diameter difference).

175/70R13 is 0.51 in taller than 145/80R13 and 30 mm wider, a 2.31% difference in overall diameter.

With the speedometer calibrated for 145/80R13, an indicated 60 mph is actually 61.4 mph on 175/70R13, and revolutions per mile change from 911 to 891.

Both sizes mount on 13-inch wheels.

Size pages

Other comparisons with 145/80R13

Other comparisons with 175/70R13

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