Tire Size Box

145/80R13 vs 185/55R14

185/55R14 compared with 145/80R13

−0.6% diameter, +1.6" width

185/55R14 is 22.01" tall vs 22.13". Within the 3% rule, so usually interchangeable.

22.1"13" rim4.6"5.7" wide
145/80R13 (solid) compared with 185/55R14 (dashed outline), drawn to scale

With 185/55R14 tires, when your speedometer says 60 mph you are really going

59.7 mph

185/55R14 is −0.12 inches (−0.6%) in overall diameter. That is within the 3% most shops and makers allow.

145/80R13185/55R14Difference%
Overall diameter22.13"22.01"−0.12"−0.6%
Section width5.71"7.28"+1.57"+27.6%
Sidewall height4.57"4.01"−0.56"−12.3%
Circumference69.54"69.15"−0.38"−0.6%
Revolutions per mile911.2916.2+5.1+0.6%

Speedometer difference

If your vehicle came with 145/80R13 and you fit 185/55R14, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph19.9 mph−0.1 mph
30 mph29.8 mph−0.2 mph
40 mph39.8 mph−0.2 mph
50 mph49.7 mph−0.3 mph
60 mph59.7 mph−0.3 mph
65 mph64.6 mph−0.4 mph
70 mph69.6 mph−0.4 mph
75 mph74.6 mph−0.4 mph
80 mph79.6 mph−0.4 mph

Each size on its own

Questions

Which is bigger, 145/80R13 or 185/55R14?
145/80R13 is taller by 0.12 inches (22.13" vs 22.01"). 185/55R14 is wider by 1.57 inches.
Can I replace 145/80R13 with 185/55R14?
Usually, yes. The diameter difference is −0.6%, 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 185/55R14 change my speedometer?
When your speedometer reads 60 mph with 185/55R14 fitted (calibrated for 145/80R13), your real speed is 59.7 mph. Your odometer will over-count miles by about 0.6%.
Will 185/55R14 lift my vehicle?
Ride height changes by half the diameter difference: −0.06 inches of ground clearance at the axle.

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