Tire Size Box

265/65R15 vs 285/65R15

285/65R15 compared with 265/65R15

+3.6% diameter, +0.8" width

285/65R15 is 29.59" tall vs 28.56". More than the 3% rule of thumb, so check carefully before switching.

28.6"15" rim6.8"10.4" wide
265/65R15 (solid) compared with 285/65R15 (dashed outline), drawn to scale

With 285/65R15 tires, when your speedometer says 60 mph you are really going

62.2 mph

285/65R15 is +1.02 inches (+3.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/65R15285/65R15Difference%
Overall diameter28.56"29.59"+1.02"+3.6%
Section width10.43"11.22"+0.79"+7.5%
Sidewall height6.78"7.29"+0.51"+7.5%
Circumference89.73"92.95"+3.22"+3.6%
Revolutions per mile706.1681.7−24.4−3.5%

Speedometer difference

If your vehicle came with 265/65R15 and you fit 285/65R15, 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 mph67.3 mph+2.3 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, 265/65R15 or 285/65R15?
285/65R15 is taller by 1.02 inches (29.59" vs 28.56"). 285/65R15 is wider by 0.79 inches.
Can I replace 265/65R15 with 285/65R15?
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 285/65R15 change my speedometer?
When your speedometer reads 60 mph with 285/65R15 fitted (calibrated for 265/65R15), your real speed is 62.2 mph. Your odometer will under-count miles by about 3.6%.
Will 285/65R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.51 inches of ground clearance at the axle.

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