Tire Size Box

245/45R22 vs 245/55R22

245/55R22 compared with 245/45R22

+6.3% diameter, 0.0" width

245/55R22 is 32.61" tall vs 30.68". More than the 3% rule of thumb, so check carefully before switching.

30.7"22" rim4.3"9.6" wide
245/45R22 (solid) compared with 245/55R22 (dashed outline), drawn to scale

With 245/55R22 tires, when your speedometer says 60 mph you are really going

63.8 mph

245/55R22 is +1.93 inches (+6.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/45R22245/55R22Difference%
Overall diameter30.68"32.61"+1.93"+6.3%
Section width9.65"9.65"0.00"0.0%
Sidewall height4.34"5.31"+0.96"+22.2%
Circumference96.39"102.45"+6.06"+6.3%
Revolutions per mile657.3618.5−38.9−5.9%

Speedometer difference

If your vehicle came with 245/45R22 and you fit 245/55R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.3 mph+1.3 mph
30 mph31.9 mph+1.9 mph
40 mph42.5 mph+2.5 mph
50 mph53.1 mph+3.1 mph
60 mph63.8 mph+3.8 mph
65 mph69.1 mph+4.1 mph
70 mph74.4 mph+4.4 mph
75 mph79.7 mph+4.7 mph
80 mph85.0 mph+5.0 mph

Each size on its own

Questions

Which is bigger, 245/45R22 or 245/55R22?
245/55R22 is taller by 1.93 inches (32.61" vs 30.68"). 245/45R22 is the same width.
Can I replace 245/45R22 with 245/55R22?
It is not recommended without checking carefully. The diameter difference is +6.3%, more than the 3% most shops and makers allow. It will throw off the speedometer and may affect ABS, stability control and clearance.
How much will 245/55R22 change my speedometer?
When your speedometer reads 60 mph with 245/55R22 fitted (calibrated for 245/45R22), your real speed is 63.8 mph. Your odometer will under-count miles by about 6.3%.
Will 245/55R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.96 inches of ground clearance at the axle.

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