Tire Size Box

335/25R21 vs 335/35R21

335/35R21 compared with 335/25R21

+9.6% diameter, 0.0" width

335/35R21 is 30.23" tall vs 27.59". More than the 3% rule of thumb, so check carefully before switching.

27.6"21" rim3.3"13.2" wide
335/25R21 (solid) compared with 335/35R21 (dashed outline), drawn to scale

With 335/35R21 tires, when your speedometer says 60 mph you are really going

65.7 mph

335/35R21 is +2.64 inches (+9.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

335/25R21335/35R21Difference%
Overall diameter27.59"30.23"+2.64"+9.6%
Section width13.19"13.19"0.00"0.0%
Sidewall height3.30"4.62"+1.32"+40.0%
Circumference86.69"94.98"+8.29"+9.6%
Revolutions per mile730.9667.1−63.8−8.7%

Speedometer difference

If your vehicle came with 335/25R21 and you fit 335/35R21, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.9 mph+1.9 mph
30 mph32.9 mph+2.9 mph
40 mph43.8 mph+3.8 mph
50 mph54.8 mph+4.8 mph
60 mph65.7 mph+5.7 mph
65 mph71.2 mph+6.2 mph
70 mph76.7 mph+6.7 mph
75 mph82.2 mph+7.2 mph
80 mph87.6 mph+7.6 mph

Each size on its own

Questions

Which is bigger, 335/25R21 or 335/35R21?
335/35R21 is taller by 2.64 inches (30.23" vs 27.59"). 335/25R21 is the same width.
Can I replace 335/25R21 with 335/35R21?
It is not recommended without checking carefully. The diameter difference is +9.6%, 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 335/35R21 change my speedometer?
When your speedometer reads 60 mph with 335/35R21 fitted (calibrated for 335/25R21), your real speed is 65.7 mph. Your odometer will under-count miles by about 9.6%.
Will 335/35R21 lift my vehicle?
Ride height changes by half the diameter difference: +1.32 inches of ground clearance at the axle.

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