Tire Size Box

205/55R17 vs 205/65R17

205/65R17 compared with 205/55R17

+6.2% diameter, 0.0" width

205/65R17 is 27.49" tall vs 25.88". More than the 3% rule of thumb, so check carefully before switching.

25.9"17" rim4.4"8.1" wide
205/55R17 (solid) compared with 205/65R17 (dashed outline), drawn to scale

With 205/65R17 tires, when your speedometer says 60 mph you are really going

63.7 mph

205/65R17 is +1.61 inches (+6.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

205/55R17205/65R17Difference%
Overall diameter25.88"27.49"+1.61"+6.2%
Section width8.07"8.07"0.00"0.0%
Sidewall height4.44"5.25"+0.81"+18.2%
Circumference81.30"86.37"+5.07"+6.2%
Revolutions per mile779.4733.6−45.8−5.9%

Speedometer difference

If your vehicle came with 205/55R17 and you fit 205/65R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.2 mph+1.2 mph
30 mph31.9 mph+1.9 mph
40 mph42.5 mph+2.5 mph
50 mph53.1 mph+3.1 mph
60 mph63.7 mph+3.7 mph
65 mph69.1 mph+4.1 mph
70 mph74.4 mph+4.4 mph
75 mph79.7 mph+4.7 mph
80 mph85.0 mph+5.0 mph

Each size on its own

Questions

Which is bigger, 205/55R17 or 205/65R17?
205/65R17 is taller by 1.61 inches (27.49" vs 25.88"). 205/55R17 is the same width.
Can I replace 205/55R17 with 205/65R17?
It is not recommended without checking carefully. The diameter difference is +6.2%, 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 205/65R17 change my speedometer?
When your speedometer reads 60 mph with 205/65R17 fitted (calibrated for 205/55R17), your real speed is 63.7 mph. Your odometer will under-count miles by about 6.2%.
Will 205/65R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.81 inches of ground clearance at the axle.

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