Tire Size Box

265/55R17 vs 265/65R17

265/65R17 compared with 265/55R17

+7.3% diameter, 0.0" width

265/65R17 is 30.56" tall vs 28.48". More than the 3% rule of thumb, so check carefully before switching.

28.5"17" rim5.7"10.4" wide
265/55R17 (solid) compared with 265/65R17 (dashed outline), drawn to scale

With 265/65R17 tires, when your speedometer says 60 mph you are really going

64.4 mph

265/65R17 is +2.09 inches (+7.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/55R17265/65R17Difference%
Overall diameter28.48"30.56"+2.09"+7.3%
Section width10.43"10.43"0.00"0.0%
Sidewall height5.74"6.78"+1.04"+18.2%
Circumference89.46"96.02"+6.56"+7.3%
Revolutions per mile708.2659.9−48.4−6.8%

Speedometer difference

If your vehicle came with 265/55R17 and you fit 265/65R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.2 mph+2.2 mph
40 mph42.9 mph+2.9 mph
50 mph53.7 mph+3.7 mph
60 mph64.4 mph+4.4 mph
65 mph69.8 mph+4.8 mph
70 mph75.1 mph+5.1 mph
75 mph80.5 mph+5.5 mph
80 mph85.9 mph+5.9 mph

Each size on its own

Questions

Which is bigger, 265/55R17 or 265/65R17?
265/65R17 is taller by 2.09 inches (30.56" vs 28.48"). 265/55R17 is the same width.
Can I replace 265/55R17 with 265/65R17?
It is not recommended without checking carefully. The diameter difference is +7.3%, 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 265/65R17 change my speedometer?
When your speedometer reads 60 mph with 265/65R17 fitted (calibrated for 265/55R17), your real speed is 64.4 mph. Your odometer will under-count miles by about 7.3%.
Will 265/65R17 lift my vehicle?
Ride height changes by half the diameter difference: +1.04 inches of ground clearance at the axle.

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