195/70R14 vs 185/65R15

185/65R15 is 0.28 in (7.1 mm) shorter than 195/70R14, a −1.13% diameter difference. With the speedometer set for 195/70R14, an indicated 60 mph is 59.3 mph on 185/65R15.

Is this a safe swap?

Diameter difference −1.13%: within the ±3% guideline

By overall diameter alone, 185/65R15 falls inside the ±3% range commonly used as a guideline when replacing 195/70R14. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 195/70R14 (24.75 in) vs 185/65R15 (24.47 in)195/70R1424.75 in × 7.68 in185/65R1524.47 in × 7.28 in
Side profile and tread width, drawn to the same scale.
195/70R14 vs 185/65R15 differences
Measurement195/70R14185/65R15Difference% diff
Overall diameter24.75 in (628.6 mm)24.47 in (621.5 mm)−0.28 in (−7.1 mm)−1.13%
Sidewall height5.37 in (136.5 mm)4.73 in (120.3 mm)−0.64 in (−16.2 mm)−11.90%
Section width7.68 in (195.0 mm)7.28 in (185.0 mm)−0.39 in (−10.0 mm)−5.13%
Circumference77.75 in (1,974.8 mm)76.87 in (1,952.5 mm)−0.88 in (−22.3 mm)−1.13%
Revolutions per mile815824+9+1.14%
True speed with the speedometer calibrated for 195/70R14
IndicatedActual on 195/70R14Actual on 185/65R15Difference
30 mph30.0 mph29.7 mph−0.3 mph
60 mph60.0 mph59.3 mph−0.7 mph
75 mph75.0 mph74.2 mph−0.8 mph

Ride-height change: 185/65R15 lowers the vehicle by 0.14 in (3.5 mm) at the axle (half the −7.1 mm diameter difference).

185/65R15 is 0.28 in shorter than 195/70R14 and 10 mm narrower, a 1.13% difference in overall diameter.

With the speedometer calibrated for 195/70R14, an indicated 60 mph is actually 59.3 mph on 185/65R15, and revolutions per mile change from 815 to 824.

185/65R15 mounts on a 15-inch wheel, a plus-1 fitment from the 14-inch wheel of 195/70R14.

Size pages

Other comparisons with 195/70R14

Other comparisons with 185/65R15

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