Tire Size Box

225/55R17 vs 225/65R17

225/65R17 compared with 225/55R17

+6.6% diameter, 0.0" width

225/65R17 is 28.52" tall vs 26.74". More than the 3% rule of thumb, so check carefully before switching.

26.7"17" rim4.9"8.9" wide
225/55R17 (solid) compared with 225/65R17 (dashed outline), drawn to scale

With 225/65R17 tires, when your speedometer says 60 mph you are really going

64.0 mph

225/65R17 is +1.77 inches (+6.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/55R17225/65R17Difference%
Overall diameter26.74"28.52"+1.77"+6.6%
Section width8.86"8.86"0.00"0.0%
Sidewall height4.87"5.76"+0.89"+18.2%
Circumference84.02"89.58"+5.57"+6.6%
Revolutions per mile754.1707.3−46.9−6.2%

Speedometer difference

If your vehicle came with 225/55R17 and you fit 225/65R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.3 mph+1.3 mph
30 mph32.0 mph+2.0 mph
40 mph42.6 mph+2.6 mph
50 mph53.3 mph+3.3 mph
60 mph64.0 mph+4.0 mph
65 mph69.3 mph+4.3 mph
70 mph74.6 mph+4.6 mph
75 mph80.0 mph+5.0 mph
80 mph85.3 mph+5.3 mph

Each size on its own

Questions

Which is bigger, 225/55R17 or 225/65R17?
225/65R17 is taller by 1.77 inches (28.52" vs 26.74"). 225/55R17 is the same width.
Can I replace 225/55R17 with 225/65R17?
It is not recommended without checking carefully. The diameter difference is +6.6%, 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 225/65R17 change my speedometer?
When your speedometer reads 60 mph with 225/65R17 fitted (calibrated for 225/55R17), your real speed is 64.0 mph. Your odometer will under-count miles by about 6.6%.
Will 225/65R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.89 inches of ground clearance at the axle.

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