Tire Size Box

335/50R21 vs 335/55R21

335/55R21 compared with 335/50R21

+3.9% diameter, 0.0" width

335/55R21 is 35.51" tall vs 34.19". More than the 3% rule of thumb, so check carefully before switching.

34.2"21" rim6.6"13.2" wide
335/50R21 (solid) compared with 335/55R21 (dashed outline), drawn to scale

With 335/55R21 tires, when your speedometer says 60 mph you are really going

62.3 mph

335/55R21 is +1.32 inches (+3.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

335/50R21335/55R21Difference%
Overall diameter34.19"35.51"+1.32"+3.9%
Section width13.19"13.19"0.00"0.0%
Sidewall height6.59"7.25"+0.66"+10.0%
Circumference107.41"111.55"+4.14"+3.9%
Revolutions per mile589.9568.0−21.9−3.7%

Speedometer difference

If your vehicle came with 335/50R21 and you fit 335/55R21, 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 mph41.5 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 mph83.1 mph+3.1 mph

Each size on its own

Questions

Which is bigger, 335/50R21 or 335/55R21?
335/55R21 is taller by 1.32 inches (35.51" vs 34.19"). 335/50R21 is the same width.
Can I replace 335/50R21 with 335/55R21?
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 335/55R21 change my speedometer?
When your speedometer reads 60 mph with 335/55R21 fitted (calibrated for 335/50R21), your real speed is 62.3 mph. Your odometer will under-count miles by about 3.9%.
Will 335/55R21 lift my vehicle?
Ride height changes by half the diameter difference: +0.66 inches of ground clearance at the axle.

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