Tire Size Box

265/25R20 vs 265/35R20

265/35R20 compared with 265/25R20

+8.3% diameter, 0.0" width

265/35R20 is 27.30" tall vs 25.22". More than the 3% rule of thumb, so check carefully before switching.

25.2"20" rim2.6"10.4" wide
265/25R20 (solid) compared with 265/35R20 (dashed outline), drawn to scale

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

65.0 mph

265/35R20 is +2.09 inches (+8.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/25R20265/35R20Difference%
Overall diameter25.22"27.30"+2.09"+8.3%
Section width10.43"10.43"0.00"0.0%
Sidewall height2.61"3.65"+1.04"+40.0%
Circumference79.22"85.78"+6.56"+8.3%
Revolutions per mile799.8738.7−61.1−7.6%

Speedometer difference

If your vehicle came with 265/25R20 and you fit 265/35R20, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.7 mph+1.7 mph
30 mph32.5 mph+2.5 mph
40 mph43.3 mph+3.3 mph
50 mph54.1 mph+4.1 mph
60 mph65.0 mph+5.0 mph
65 mph70.4 mph+5.4 mph
70 mph75.8 mph+5.8 mph
75 mph81.2 mph+6.2 mph
80 mph86.6 mph+6.6 mph

Each size on its own

Questions

Which is bigger, 265/25R20 or 265/35R20?
265/35R20 is taller by 2.09 inches (27.30" vs 25.22"). 265/25R20 is the same width.
Can I replace 265/25R20 with 265/35R20?
It is not recommended without checking carefully. The diameter difference is +8.3%, 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 265/25R20), your real speed is 65.0 mph. Your odometer will under-count miles by about 8.3%.
Will 265/35R20 lift my vehicle?
Ride height changes by half the diameter difference: +1.04 inches of ground clearance at the axle.

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