TireSizeCheck

235/65R17 vs 225/60R17

Fitment assessment

Fitment not determined

Diameter change

−4.8%

Overall diameter changes 4.8%; 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

27.63″

was 29.03″

True speed at an indicated 60

57.1 mph

your speedo reads high

Revolutions per mile

730

was 695, +35

Measurement 235/65R17 225/60R17 Change
Overall diameter 29.03″ 27.63″ −1.40″ (−4.8%)
Sidewall height 6.01″ (152.8 mm) 5.31″ (135.0 mm) −17.8 mm
Tread width 235 mm 225 mm −10 mm
Circumference 91.19″ 86.80″ −4.39″
Revs per mile 695 730 +35
Speedometer error baseline −4.8% reads high

Diameter overlay

235/65R17 225/60R17

Speedometer check

With 225/60R17 fitted, when the speedometer shows the indicated speed, your actual speed is:

25 mph shown

23.8 mph actual

35 mph shown

33.3 mph actual

45 mph shown

42.8 mph actual

55 mph shown

52.4 mph actual

65 mph shown

61.9 mph actual

75 mph shown

71.4 mph actual

Common questions

Will 225/60R17 fit instead of 235/65R17?
Overall diameter changes 4.8%; 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 29.03″ to 27.63″, a change of −4.8%. 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 225/60R17?
At an indicated 60 mph you are really doing about 57.1 mph, a −4.8% error. The speedometer reads high, so you are going slower than it shows.
What is the difference in revolutions per mile between 235/65R17 and 225/60R17?
235/65R17 turns about 695 times per mile and 225/60R17 turns about 730, a difference of +35. Your speedometer and odometer both count rotations, so this number is what throws them off.