155/70R13 vs 165/70R13

165/70R13 is 0.55 in (14.0 mm) taller than 155/70R13, a +2.56% diameter difference. With the speedometer set for 155/70R13, an indicated 60 mph is 61.5 mph on 165/70R13.

Is this a safe swap?

Diameter difference +2.56%: within the ±3% guideline

By overall diameter alone, 165/70R13 falls inside the ±3% range commonly used as a guideline when replacing 155/70R13. 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.

155/70R13 vs 165/70R13 differences
Measurement	155/70R13	165/70R13	Difference	% diff
Overall diameter	21.54 in (547.2 mm)	22.09 in (561.2 mm)	+0.55 in (+14.0 mm)	+2.56%
Sidewall height	4.27 in (108.5 mm)	4.55 in (115.5 mm)	+0.28 in (+7.0 mm)	+6.45%
Section width	6.10 in (155.0 mm)	6.50 in (165.0 mm)	+0.39 in (+10.0 mm)	+6.45%
Circumference	67.68 in (1,719.1 mm)	69.41 in (1,763.1 mm)	+1.73 in (+44.0 mm)	+2.56%
Revolutions per mile	936	913	−23	−2.49%

True speed with the speedometer calibrated for 155/70R13
Indicated	Actual on 155/70R13	Actual on 165/70R13	Difference
30 mph	30.0 mph	30.8 mph	+0.8 mph
60 mph	60.0 mph	61.5 mph	+1.5 mph
75 mph	75.0 mph	76.9 mph	+1.9 mph

Ride-height change: 165/70R13 raises the vehicle by 0.28 in (7.0 mm) at the axle (half the +14.0 mm diameter difference).

165/70R13 is 0.55 in taller than 155/70R13 and 10 mm wider, a 2.56% difference in overall diameter.

With the speedometer calibrated for 155/70R13, an indicated 60 mph is actually 61.5 mph on 165/70R13, and revolutions per mile change from 936 to 913.

Both sizes mount on 13-inch wheels.

Size pages

Other comparisons with 155/70R13

Other comparisons with 165/70R13

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