Tire Size Box

265/25R21 vs 265/35R21

265/35R21 compared with 265/25R21

+8.0% diameter, 0.0" width

265/35R21 is 28.30" tall vs 26.22". More than the 3% rule of thumb, so check carefully before switching.

26.2"21" rim2.6"10.4" wide
265/25R21 (solid) compared with 265/35R21 (dashed outline), drawn to scale

With 265/35R21 tires, when your speedometer says 60 mph you are really going

64.8 mph

265/35R21 is +2.09 inches (+8.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/25R21265/35R21Difference%
Overall diameter26.22"28.30"+2.09"+8.0%
Section width10.43"10.43"0.00"0.0%
Sidewall height2.61"3.65"+1.04"+40.0%
Circumference82.36"88.92"+6.56"+8.0%
Revolutions per mile769.3712.6−56.7−7.4%

Speedometer difference

If your vehicle came with 265/25R21 and you fit 265/35R21, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.6 mph+1.6 mph
30 mph32.4 mph+2.4 mph
40 mph43.2 mph+3.2 mph
50 mph54.0 mph+4.0 mph
60 mph64.8 mph+4.8 mph
65 mph70.2 mph+5.2 mph
70 mph75.6 mph+5.6 mph
75 mph81.0 mph+6.0 mph
80 mph86.4 mph+6.4 mph

Each size on its own

Questions

Which is bigger, 265/25R21 or 265/35R21?
265/35R21 is taller by 2.09 inches (28.30" vs 26.22"). 265/25R21 is the same width.
Can I replace 265/25R21 with 265/35R21?
It is not recommended without checking carefully. The diameter difference is +8.0%, 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 265/35R21 change my speedometer?
When your speedometer reads 60 mph with 265/35R21 fitted (calibrated for 265/25R21), your real speed is 64.8 mph. Your odometer will under-count miles by about 8.0%.
Will 265/35R21 lift my vehicle?
Ride height changes by half the diameter difference: +1.04 inches of ground clearance at the axle.

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