Tire Size Box

275/50R17 vs 275/55R17

275/55R17 compared with 275/50R17

+3.9% diameter, 0.0" width

275/55R17 is 28.91" tall vs 27.83". More than the 3% rule of thumb, so check carefully before switching.

27.8"17" rim5.4"10.8" wide
275/50R17 (solid) compared with 275/55R17 (dashed outline), drawn to scale

With 275/55R17 tires, when your speedometer says 60 mph you are really going

62.3 mph

275/55R17 is +1.08 inches (+3.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

275/50R17275/55R17Difference%
Overall diameter27.83"28.91"+1.08"+3.9%
Section width10.83"10.83"0.00"0.0%
Sidewall height5.41"5.95"+0.54"+10.0%
Circumference87.42"90.82"+3.40"+3.9%
Revolutions per mile724.8697.6−27.1−3.7%

Speedometer difference

If your vehicle came with 275/50R17 and you fit 275/55R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.2 mph+1.2 mph
40 mph41.6 mph+1.6 mph
50 mph51.9 mph+1.9 mph
60 mph62.3 mph+2.3 mph
65 mph67.5 mph+2.5 mph
70 mph72.7 mph+2.7 mph
75 mph77.9 mph+2.9 mph
80 mph83.1 mph+3.1 mph

Each size on its own

Questions

Which is bigger, 275/50R17 or 275/55R17?
275/55R17 is taller by 1.08 inches (28.91" vs 27.83"). 275/50R17 is the same width.
Can I replace 275/50R17 with 275/55R17?
It is not recommended without checking carefully. The diameter difference is +3.9%, 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 275/55R17 change my speedometer?
When your speedometer reads 60 mph with 275/55R17 fitted (calibrated for 275/50R17), your real speed is 62.3 mph. Your odometer will under-count miles by about 3.9%.
Will 275/55R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.54 inches of ground clearance at the axle.

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