Tire Size Box

245/70R17 vs 265/70R17

265/70R17 compared with 245/70R17

+3.6% diameter, +0.8" width

265/70R17 is 31.61" tall vs 30.50". More than the 3% rule of thumb, so check carefully before switching.

30.5"17" rim6.8"9.6" wide
245/70R17 (solid) compared with 265/70R17 (dashed outline), drawn to scale

With 265/70R17 tires, when your speedometer says 60 mph you are really going

62.2 mph

265/70R17 is +1.10 inches (+3.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/70R17265/70R17Difference%
Overall diameter30.50"31.61"+1.10"+3.6%
Section width9.65"10.43"+0.79"+8.2%
Sidewall height6.75"7.30"+0.55"+8.2%
Circumference95.83"99.29"+3.46"+3.6%
Revolutions per mile661.2638.1−23.1−3.5%

Speedometer difference

If your vehicle came with 245/70R17 and you fit 265/70R17, 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, 245/70R17 or 265/70R17?
265/70R17 is taller by 1.10 inches (31.61" vs 30.50"). 265/70R17 is wider by 0.79 inches.
Can I replace 245/70R17 with 265/70R17?
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 265/70R17 change my speedometer?
When your speedometer reads 60 mph with 265/70R17 fitted (calibrated for 245/70R17), your real speed is 62.2 mph. Your odometer will under-count miles by about 3.6%.
Will 265/70R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.55 inches of ground clearance at the axle.

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