Tire Size Box

175/55R16 vs 175/65R16

175/65R16 compared with 175/55R16

+5.8% diameter, 0.0" width

175/65R16 is 24.96" tall vs 23.58". More than the 3% rule of thumb, so check carefully before switching.

23.6"16" rim3.8"6.9" wide
175/55R16 (solid) compared with 175/65R16 (dashed outline), drawn to scale

With 175/65R16 tires, when your speedometer says 60 mph you are really going

63.5 mph

175/65R16 is +1.38 inches (+5.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

175/55R16175/65R16Difference%
Overall diameter23.58"24.96"+1.38"+5.8%
Section width6.89"6.89"0.00"0.0%
Sidewall height3.79"4.48"+0.69"+18.2%
Circumference74.07"78.40"+4.33"+5.8%
Revolutions per mile855.4808.1−47.2−5.5%

Speedometer difference

If your vehicle came with 175/55R16 and you fit 175/65R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.2 mph+1.2 mph
30 mph31.8 mph+1.8 mph
40 mph42.3 mph+2.3 mph
50 mph52.9 mph+2.9 mph
60 mph63.5 mph+3.5 mph
65 mph68.8 mph+3.8 mph
70 mph74.1 mph+4.1 mph
75 mph79.4 mph+4.4 mph
80 mph84.7 mph+4.7 mph

Each size on its own

Questions

Which is bigger, 175/55R16 or 175/65R16?
175/65R16 is taller by 1.38 inches (24.96" vs 23.58"). 175/55R16 is the same width.
Can I replace 175/55R16 with 175/65R16?
It is not recommended without checking carefully. The diameter difference is +5.8%, 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 175/65R16 change my speedometer?
When your speedometer reads 60 mph with 175/65R16 fitted (calibrated for 175/55R16), your real speed is 63.5 mph. Your odometer will under-count miles by about 5.8%.
Will 175/65R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.69 inches of ground clearance at the axle.

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