Tire Size Box

335/45R21 vs 335/50R21

335/50R21 compared with 335/45R21

+4.0% diameter, 0.0" width

335/50R21 is 34.19" tall vs 32.87". More than the 3% rule of thumb, so check carefully before switching.

32.9"21" rim5.9"13.2" wide
335/45R21 (solid) compared with 335/50R21 (dashed outline), drawn to scale

With 335/50R21 tires, when your speedometer says 60 mph you are really going

62.4 mph

335/50R21 is +1.32 inches (+4.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

335/45R21335/50R21Difference%
Overall diameter32.87"34.19"+1.32"+4.0%
Section width13.19"13.19"0.00"0.0%
Sidewall height5.94"6.59"+0.66"+11.1%
Circumference103.26"107.41"+4.14"+4.0%
Revolutions per mile613.6589.9−23.7−3.9%

Speedometer difference

If your vehicle came with 335/45R21 and you fit 335/50R21, 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 mph52.0 mph+2.0 mph
60 mph62.4 mph+2.4 mph
65 mph67.6 mph+2.6 mph
70 mph72.8 mph+2.8 mph
75 mph78.0 mph+3.0 mph
80 mph83.2 mph+3.2 mph

Each size on its own

Questions

Which is bigger, 335/45R21 or 335/50R21?
335/50R21 is taller by 1.32 inches (34.19" vs 32.87"). 335/45R21 is the same width.
Can I replace 335/45R21 with 335/50R21?
It is not recommended without checking carefully. The diameter difference is +4.0%, 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 335/50R21 change my speedometer?
When your speedometer reads 60 mph with 335/50R21 fitted (calibrated for 335/45R21), your real speed is 62.4 mph. Your odometer will under-count miles by about 4.0%.
Will 335/50R21 lift my vehicle?
Ride height changes by half the diameter difference: +0.66 inches of ground clearance at the axle.

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