Tire Size Box

345/30R20 vs 335/35R20

335/35R20 compared with 345/30R20

+3.8% diameter, −0.4" width

335/35R20 is 29.23" tall vs 28.15". More than the 3% rule of thumb, so check carefully before switching.

28.1"20" rim4.1"13.6" wide
345/30R20 (solid) compared with 335/35R20 (dashed outline), drawn to scale

With 335/35R20 tires, when your speedometer says 60 mph you are really going

62.3 mph

335/35R20 is +1.08 inches (+3.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

345/30R20335/35R20Difference%
Overall diameter28.15"29.23"+1.08"+3.8%
Section width13.58"13.19"−0.39"−2.9%
Sidewall height4.07"4.62"+0.54"+13.3%
Circumference88.43"91.84"+3.40"+3.8%
Revolutions per mile716.5689.9−26.5−3.7%

Speedometer difference

If your vehicle came with 345/30R20 and you fit 335/35R20, 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, 345/30R20 or 335/35R20?
335/35R20 is taller by 1.08 inches (29.23" vs 28.15"). 345/30R20 is wider by 0.39 inches.
Can I replace 345/30R20 with 335/35R20?
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 335/35R20 change my speedometer?
When your speedometer reads 60 mph with 335/35R20 fitted (calibrated for 345/30R20), your real speed is 62.3 mph. Your odometer will under-count miles by about 3.8%.
Will 335/35R20 lift my vehicle?
Ride height changes by half the diameter difference: +0.54 inches of ground clearance at the axle.

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