TireSizeCheck

215/60R17 vs 215/55R17

Fitment assessment

Fitment not determined

Diameter change

−3.1%

Overall diameter changes 3.1%; section width changes 0 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

26.31″

was 27.16″

True speed at an indicated 60

58.1 mph

your speedo reads high

Revolutions per mile

767

was 743, +24

Measurement 215/60R17 215/55R17 Change
Overall diameter 27.16″ 26.31″ −0.85″ (−3.1%)
Sidewall height 5.08″ (129.0 mm) 4.66″ (118.3 mm) −10.8 mm
Tread width 215 mm 215 mm +0 mm
Circumference 85.32″ 82.66″ −2.66″
Revs per mile 743 767 +24
Speedometer error baseline −3.1% reads high

Diameter overlay

215/60R17 215/55R17

Speedometer check

With 215/55R17 fitted, when the speedometer shows the indicated speed, your actual speed is:

25 mph shown

24.2 mph actual

35 mph shown

33.9 mph actual

45 mph shown

43.6 mph actual

55 mph shown

53.3 mph actual

65 mph shown

63.0 mph actual

75 mph shown

72.7 mph actual

Common questions

Will 215/55R17 fit instead of 215/60R17?
Overall diameter changes 3.1%; section width changes 0 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 27.16″ to 26.31″, a change of −3.1%. 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 215/55R17?
At an indicated 60 mph you are really doing about 58.1 mph, a −3.1% error. The speedometer reads high, so you are going slower than it shows.
What is the difference in revolutions per mile between 215/60R17 and 215/55R17?
215/60R17 turns about 743 times per mile and 215/55R17 turns about 767, a difference of +24. Your speedometer and odometer both count rotations, so this number is what throws them off.