Tire Size Box

265/50R17 vs 265/55R17

265/55R17 compared with 265/50R17

+3.8% diameter, 0.0" width

265/55R17 is 28.48" tall vs 27.43". More than the 3% rule of thumb, so check carefully before switching.

27.4"17" rim5.2"10.4" wide
265/50R17 (solid) compared with 265/55R17 (dashed outline), drawn to scale

With 265/55R17 tires, when your speedometer says 60 mph you are really going

62.3 mph

265/55R17 is +1.04 inches (+3.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/50R17265/55R17Difference%
Overall diameter27.43"28.48"+1.04"+3.8%
Section width10.43"10.43"0.00"0.0%
Sidewall height5.22"5.74"+0.52"+10.0%
Circumference86.18"89.46"+3.28"+3.8%
Revolutions per mile735.2708.2−26.9−3.7%

Speedometer difference

If your vehicle came with 265/50R17 and you fit 265/55R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.1 mph+1.1 mph
40 mph41.5 mph+1.5 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 mph83.0 mph+3.0 mph

Each size on its own

Questions

Which is bigger, 265/50R17 or 265/55R17?
265/55R17 is taller by 1.04 inches (28.48" vs 27.43"). 265/50R17 is the same width.
Can I replace 265/50R17 with 265/55R17?
It is not recommended without checking carefully. The diameter difference is +3.8%, 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 265/55R17 change my speedometer?
When your speedometer reads 60 mph with 265/55R17 fitted (calibrated for 265/50R17), your real speed is 62.3 mph. Your odometer will under-count miles by about 3.8%.
Will 265/55R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.52 inches of ground clearance at the axle.

Other comparisons