Tire Size Box

275/30R20 vs 265/35R20

265/35R20 compared with 275/30R20

+3.0% diameter, −0.4" width

265/35R20 is 27.30" tall vs 26.50". More than the 3% rule of thumb, so check carefully before switching.

26.5"20" rim3.2"10.8" wide
275/30R20 (solid) compared with 265/35R20 (dashed outline), drawn to scale

With 265/35R20 tires, when your speedometer says 60 mph you are really going

61.8 mph

265/35R20 is +0.81 inches (+3.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

275/30R20265/35R20Difference%
Overall diameter26.50"27.30"+0.81"+3.0%
Section width10.83"10.43"−0.39"−3.6%
Sidewall height3.25"3.65"+0.40"+12.4%
Circumference83.24"85.78"+2.54"+3.0%
Revolutions per mile761.2738.7−22.5−3.0%

Speedometer difference

If your vehicle came with 275/30R20 and you fit 265/35R20, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph30.9 mph+0.9 mph
40 mph41.2 mph+1.2 mph
50 mph51.5 mph+1.5 mph
60 mph61.8 mph+1.8 mph
65 mph67.0 mph+2.0 mph
70 mph72.1 mph+2.1 mph
75 mph77.3 mph+2.3 mph
80 mph82.4 mph+2.4 mph

Each size on its own

Questions

Which is bigger, 275/30R20 or 265/35R20?
265/35R20 is taller by 0.81 inches (27.30" vs 26.50"). 275/30R20 is wider by 0.39 inches.
Can I replace 275/30R20 with 265/35R20?
It is not recommended without checking carefully. The diameter difference is +3.0%, 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 265/35R20 change my speedometer?
When your speedometer reads 60 mph with 265/35R20 fitted (calibrated for 275/30R20), your real speed is 61.8 mph. Your odometer will under-count miles by about 3.0%.
Will 265/35R20 lift my vehicle?
Ride height changes by half the diameter difference: +0.40 inches of ground clearance at the axle.

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