Tire Size Box

245/85R15 vs 265/85R15

265/85R15 compared with 245/85R15

+4.3% diameter, +0.8" width

265/85R15 is 32.74" tall vs 31.40". More than the 3% rule of thumb, so check carefully before switching.

31.4"15" rim8.2"9.6" wide
245/85R15 (solid) compared with 265/85R15 (dashed outline), drawn to scale

With 265/85R15 tires, when your speedometer says 60 mph you are really going

62.6 mph

265/85R15 is +1.34 inches (+4.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/85R15265/85R15Difference%
Overall diameter31.40"32.74"+1.34"+4.3%
Section width9.65"10.43"+0.79"+8.2%
Sidewall height8.20"8.87"+0.67"+8.2%
Circumference98.64"102.84"+4.21"+4.3%
Revolutions per mile642.3616.1−26.3−4.1%

Speedometer difference

If your vehicle came with 245/85R15 and you fit 265/85R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.3 mph+1.3 mph
40 mph41.7 mph+1.7 mph
50 mph52.1 mph+2.1 mph
60 mph62.6 mph+2.6 mph
65 mph67.8 mph+2.8 mph
70 mph73.0 mph+3.0 mph
75 mph78.2 mph+3.2 mph
80 mph83.4 mph+3.4 mph

Each size on its own

Questions

Which is bigger, 245/85R15 or 265/85R15?
265/85R15 is taller by 1.34 inches (32.74" vs 31.40"). 265/85R15 is wider by 0.79 inches.
Can I replace 245/85R15 with 265/85R15?
It is not recommended without checking carefully. The diameter difference is +4.3%, 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 265/85R15 change my speedometer?
When your speedometer reads 60 mph with 265/85R15 fitted (calibrated for 245/85R15), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.3%.
Will 265/85R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.67 inches of ground clearance at the axle.

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