Tire Size Box

225/50R17 vs 225/55R17

225/55R17 compared with 225/50R17

+3.4% diameter, 0.0" width

225/55R17 is 26.74" tall vs 25.86". More than the 3% rule of thumb, so check carefully before switching.

25.9"17" rim4.4"8.9" wide
225/50R17 (solid) compared with 225/55R17 (dashed outline), drawn to scale

With 225/55R17 tires, when your speedometer says 60 mph you are really going

62.1 mph

225/55R17 is +0.89 inches (+3.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/50R17225/55R17Difference%
Overall diameter25.86"26.74"+0.89"+3.4%
Section width8.86"8.86"0.00"0.0%
Sidewall height4.43"4.87"+0.44"+10.0%
Circumference81.24"84.02"+2.78"+3.4%
Revolutions per mile779.9754.1−25.8−3.3%

Speedometer difference

If your vehicle came with 225/50R17 and you fit 225/55R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.4 mph+1.4 mph
50 mph51.7 mph+1.7 mph
60 mph62.1 mph+2.1 mph
65 mph67.2 mph+2.2 mph
70 mph72.4 mph+2.4 mph
75 mph77.6 mph+2.6 mph
80 mph82.7 mph+2.7 mph

Each size on its own

Questions

Which is bigger, 225/50R17 or 225/55R17?
225/55R17 is taller by 0.89 inches (26.74" vs 25.86"). 225/50R17 is the same width.
Can I replace 225/50R17 with 225/55R17?
It is not recommended without checking carefully. The diameter difference is +3.4%, 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 225/55R17 change my speedometer?
When your speedometer reads 60 mph with 225/55R17 fitted (calibrated for 225/50R17), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.4%.
Will 225/55R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.44 inches of ground clearance at the axle.

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