Tire Size Box

335/35R20 vs 335/45R20

335/45R20 compared with 335/35R20

+9.0% diameter, 0.0" width

335/45R20 is 31.87" tall vs 29.23". More than the 3% rule of thumb, so check carefully before switching.

29.2"20" rim4.6"13.2" wide
335/35R20 (solid) compared with 335/45R20 (dashed outline), drawn to scale

With 335/45R20 tires, when your speedometer says 60 mph you are really going

65.4 mph

335/45R20 is +2.64 inches (+9.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

335/35R20335/45R20Difference%
Overall diameter29.23"31.87"+2.64"+9.0%
Section width13.19"13.19"0.00"0.0%
Sidewall height4.62"5.94"+1.32"+28.6%
Circumference91.84"100.12"+8.29"+9.0%
Revolutions per mile689.9632.8−57.1−8.3%

Speedometer difference

If your vehicle came with 335/35R20 and you fit 335/45R20, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.8 mph+1.8 mph
30 mph32.7 mph+2.7 mph
40 mph43.6 mph+3.6 mph
50 mph54.5 mph+4.5 mph
60 mph65.4 mph+5.4 mph
65 mph70.9 mph+5.9 mph
70 mph76.3 mph+6.3 mph
75 mph81.8 mph+6.8 mph
80 mph87.2 mph+7.2 mph

Each size on its own

Questions

Which is bigger, 335/35R20 or 335/45R20?
335/45R20 is taller by 2.64 inches (31.87" vs 29.23"). 335/35R20 is the same width.
Can I replace 335/35R20 with 335/45R20?
It is not recommended without checking carefully. The diameter difference is +9.0%, 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 335/45R20 change my speedometer?
When your speedometer reads 60 mph with 335/45R20 fitted (calibrated for 335/35R20), your real speed is 65.4 mph. Your odometer will under-count miles by about 9.0%.
Will 335/45R20 lift my vehicle?
Ride height changes by half the diameter difference: +1.32 inches of ground clearance at the axle.

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