Tire Size Box

225/55R16 vs 225/65R16

225/65R16 compared with 225/55R16

+6.9% diameter, 0.0" width

225/65R16 is 27.52" tall vs 25.74". More than the 3% rule of thumb, so check carefully before switching.

25.7"16" rim4.9"8.9" wide
225/55R16 (solid) compared with 225/65R16 (dashed outline), drawn to scale

With 225/65R16 tires, when your speedometer says 60 mph you are really going

64.1 mph

225/65R16 is +1.77 inches (+6.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/55R16225/65R16Difference%
Overall diameter25.74"27.52"+1.77"+6.9%
Section width8.86"8.86"0.00"0.0%
Sidewall height4.87"5.76"+0.89"+18.2%
Circumference80.88"86.44"+5.57"+6.9%
Revolutions per mile783.4733.0−50.4−6.4%

Speedometer difference

If your vehicle came with 225/55R16 and you fit 225/65R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.4 mph+1.4 mph
30 mph32.1 mph+2.1 mph
40 mph42.8 mph+2.8 mph
50 mph53.4 mph+3.4 mph
60 mph64.1 mph+4.1 mph
65 mph69.5 mph+4.5 mph
70 mph74.8 mph+4.8 mph
75 mph80.2 mph+5.2 mph
80 mph85.5 mph+5.5 mph

Each size on its own

Questions

Which is bigger, 225/55R16 or 225/65R16?
225/65R16 is taller by 1.77 inches (27.52" vs 25.74"). 225/55R16 is the same width.
Can I replace 225/55R16 with 225/65R16?
It is not recommended without checking carefully. The diameter difference is +6.9%, 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 225/65R16 change my speedometer?
When your speedometer reads 60 mph with 225/65R16 fitted (calibrated for 225/55R16), your real speed is 64.1 mph. Your odometer will under-count miles by about 6.9%.
Will 225/65R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.89 inches of ground clearance at the axle.

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