TireSizeCheck

205/65R15 vs 195/65R15

Fitment assessment

Fitment not determined

Diameter change

−2.0%

Overall diameter changes 2.0%; section width changes -10 mm. Diameter comparison alone cannot confirm fitment. Verify the vehicle maker's approved rim width, tire load and speed ratings, and clearance at full steering lock and suspension compression. Confirm any possible ABS, traction-control, speedometer, and drivetrain effects with the vehicle maker or a qualified tire professional.

New overall diameter

24.98″

was 25.49″

True speed at an indicated 60

58.8 mph

your speedo reads high

Revolutions per mile

807

was 791, +16

Measurement 205/65R15 195/65R15 Change
Overall diameter 25.49″ 24.98″ −0.51″ (−2.0%)
Sidewall height 5.25″ (133.3 mm) 4.99″ (126.8 mm) −6.5 mm
Tread width 205 mm 195 mm −10 mm
Circumference 80.09″ 78.48″ −1.61″
Revs per mile 791 807 +16
Speedometer error baseline −2.0% reads high

Diameter overlay

205/65R15 195/65R15

Speedometer check

With 195/65R15 fitted, when the speedometer shows the indicated speed, your actual speed is:

25 mph shown

24.5 mph actual

35 mph shown

34.3 mph actual

45 mph shown

44.1 mph actual

55 mph shown

53.9 mph actual

65 mph shown

63.7 mph actual

75 mph shown

73.5 mph actual

Common questions

Will 195/65R15 fit instead of 205/65R15?
Overall diameter changes 2.0%; section width changes -10 mm. Diameter comparison alone cannot confirm fitment. Verify the vehicle maker's approved rim width, tire load and speed ratings, and clearance at full steering lock and suspension compression. Confirm any possible ABS, traction-control, speedometer, and drivetrain effects with the vehicle maker or a qualified tire professional. Overall diameter goes from 25.49″ to 24.98″, a change of −2.0%. The rule of thumb most shops use: under 3% is fine, 3 to 5% needs a clearance check, over 5% needs recalibration.
How far off will my speedometer read on 195/65R15?
At an indicated 60 mph you are really doing about 58.8 mph, a −2.0% error. The speedometer reads high, so you are going slower than it shows.
What is the difference in revolutions per mile between 205/65R15 and 195/65R15?
205/65R15 turns about 791 times per mile and 195/65R15 turns about 807, a difference of +16. Your speedometer and odometer both count rotations, so this number is what throws them off.