Tire Size Box

245/80R15 vs 265/80R15

265/80R15 compared with 245/80R15

+4.1% diameter, +0.8" width

265/80R15 is 31.69" tall vs 30.43". More than the 3% rule of thumb, so check carefully before switching.

30.4"15" rim7.7"9.6" wide
245/80R15 (solid) compared with 265/80R15 (dashed outline), drawn to scale

With 265/80R15 tires, when your speedometer says 60 mph you are really going

62.5 mph

265/80R15 is +1.26 inches (+4.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/80R15265/80R15Difference%
Overall diameter30.43"31.69"+1.26"+4.1%
Section width9.65"10.43"+0.79"+8.2%
Sidewall height7.72"8.35"+0.63"+8.2%
Circumference95.61"99.57"+3.96"+4.1%
Revolutions per mile662.7636.4−26.3−4.0%

Speedometer difference

If your vehicle came with 245/80R15 and you fit 265/80R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.2 mph+1.2 mph
40 mph41.7 mph+1.7 mph
50 mph52.1 mph+2.1 mph
60 mph62.5 mph+2.5 mph
65 mph67.7 mph+2.7 mph
70 mph72.9 mph+2.9 mph
75 mph78.1 mph+3.1 mph
80 mph83.3 mph+3.3 mph

Each size on its own

Questions

Which is bigger, 245/80R15 or 265/80R15?
265/80R15 is taller by 1.26 inches (31.69" vs 30.43"). 265/80R15 is wider by 0.79 inches.
Can I replace 245/80R15 with 265/80R15?
It is not recommended without checking carefully. The diameter difference is +4.1%, 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 265/80R15 change my speedometer?
When your speedometer reads 60 mph with 265/80R15 fitted (calibrated for 245/80R15), your real speed is 62.5 mph. Your odometer will under-count miles by about 4.1%.
Will 265/80R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.63 inches of ground clearance at the axle.

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