Tire Size Box

265/75R17 vs 285/75R17

285/75R17 compared with 265/75R17

+3.6% diameter, +0.8" width

285/75R17 is 33.83" tall vs 32.65". More than the 3% rule of thumb, so check carefully before switching.

32.6"17" rim7.8"10.4" wide
265/75R17 (solid) compared with 285/75R17 (dashed outline), drawn to scale

With 285/75R17 tires, when your speedometer says 60 mph you are really going

62.2 mph

285/75R17 is +1.18 inches (+3.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/75R17285/75R17Difference%
Overall diameter32.65"33.83"+1.18"+3.6%
Section width10.43"11.22"+0.79"+7.5%
Sidewall height7.82"8.42"+0.59"+7.5%
Circumference102.57"106.28"+3.71"+3.6%
Revolutions per mile617.7596.1−21.6−3.5%

Speedometer difference

If your vehicle came with 265/75R17 and you fit 285/75R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.1 mph+1.1 mph
40 mph41.4 mph+1.4 mph
50 mph51.8 mph+1.8 mph
60 mph62.2 mph+2.2 mph
65 mph67.4 mph+2.4 mph
70 mph72.5 mph+2.5 mph
75 mph77.7 mph+2.7 mph
80 mph82.9 mph+2.9 mph

Each size on its own

Questions

Which is bigger, 265/75R17 or 285/75R17?
285/75R17 is taller by 1.18 inches (33.83" vs 32.65"). 285/75R17 is wider by 0.79 inches.
Can I replace 265/75R17 with 285/75R17?
It is not recommended without checking carefully. The diameter difference is +3.6%, 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 285/75R17 change my speedometer?
When your speedometer reads 60 mph with 285/75R17 fitted (calibrated for 265/75R17), your real speed is 62.2 mph. Your odometer will under-count miles by about 3.6%.
Will 285/75R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.59 inches of ground clearance at the axle.

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