Tire Size Box

175/75R14 vs 215/55R15

215/55R15 compared with 175/75R14

−0.1% diameter, +1.6" width

215/55R15 is 24.31" tall vs 24.33". Within the 3% rule, so usually interchangeable.

24.3"14" rim5.2"6.9" wide
175/75R14 (solid) compared with 215/55R15 (dashed outline), drawn to scale

With 215/55R15 tires, when your speedometer says 60 mph you are really going

59.9 mph

215/55R15 is −0.02 inches (−0.1%) in overall diameter. That is within the 3% most shops and makers allow.

175/75R14215/55R15Difference%
Overall diameter24.33"24.31"−0.02"−0.1%
Section width6.89"8.46"+1.57"+22.9%
Sidewall height5.17"4.66"−0.51"−9.9%
Circumference76.45"76.38"−0.07"−0.1%
Revolutions per mile828.8829.6+0.8+0.1%

Speedometer difference

If your vehicle came with 175/75R14 and you fit 215/55R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.0 mph0.0 mph
30 mph30.0 mph0.0 mph
40 mph40.0 mph0.0 mph
50 mph50.0 mph0.0 mph
60 mph59.9 mph−0.1 mph
65 mph64.9 mph−0.1 mph
70 mph69.9 mph−0.1 mph
75 mph74.9 mph−0.1 mph
80 mph79.9 mph−0.1 mph

Each size on its own

Questions

Which is bigger, 175/75R14 or 215/55R15?
175/75R14 is taller by 0.02 inches (24.33" vs 24.31"). 215/55R15 is wider by 1.57 inches.
Can I replace 175/75R14 with 215/55R15?
Usually, yes. The diameter difference is −0.1%, inside the 3% rule of thumb most tire shops use. Check that the wider or taller tire clears your suspension and fenders, and that its load index meets your placard.
How much will 215/55R15 change my speedometer?
When your speedometer reads 60 mph with 215/55R15 fitted (calibrated for 175/75R14), your real speed is 59.9 mph. Your odometer will over-count miles by about 0.1%.
Will 215/55R15 lift my vehicle?
Ride height changes by half the diameter difference: −0.01 inches of ground clearance at the axle.

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