195/65R15 vs 185/65R15Tire Size Comparison

Safe

The 2.0% diameter difference is within the accepted 3% tolerance.

195/65R15635mm dia185/65R15622mm dia-6.5mm

Comparison Details

Overall Diameter634.5 vs 621.5 mm (-13.0 mm)
Diameter Difference-2.05%
Section Width195 vs 185 mm (-10 mm)
Sidewall Height126.8 vs 120.3 mm (-6.5 mm)
Circumference1993.3 vs 1952.5 mm
Clearance Change-6.5 mm
Speedometer Error-2.05%
Revs/Mile807 vs 824

Speedometer Correction

When switching from 195/65R15 to 185/65R15, your speedometer will differ from actual speed.

SpeedometerActual SpeedDifference
30 km/h29.4 km/h-0.6 km/h
40 km/h39.2 km/h-0.8 km/h
50 km/h49.0 km/h-1.0 km/h
60 km/h58.8 km/h-1.2 km/h
70 km/h68.6 km/h-1.4 km/h
80 km/h78.4 km/h-1.6 km/h
90 km/h88.2 km/h-1.8 km/h
100 km/h98.0 km/h-2.0 km/h
110 km/h107.7 km/h-2.3 km/h
120 km/h117.5 km/h-2.5 km/h
130 km/h127.3 km/h-2.7 km/h

Individual Tire Size Details

Practical Guidance

Switching from 195/65R15 to 185/65R15 is within the industry-accepted 3% diameter tolerance. Your speedometer, ABS, and traction control should function normally. Both sizes fit the same 15-inch rim, so no wheel change is needed.

The 3% diameter tolerance is a widely accepted industry guideline referenced by the ETRTO and most vehicle manufacturers. When in doubt, consult your vehicle's owner's manual or a qualified tire professional. For U.S. tire safety standards and recalls, see the NHTSA Tire Safety page.

Frequently Asked Questions

Safe. The overall diameter differs by -2.05%, width changes by -10mm.

Speedometer error will be -2.05%. At an indicated 100 km/h, actual speed is about 98.0 km/h.

Ground clearance changes by -6.5mm per side.