Tire Size Box

245/55R16 vs 245/65R16

245/65R16 compared with 245/55R16

+7.2% diameter, 0.0" width

245/65R16 is 28.54" tall vs 26.61". More than the 3% rule of thumb, so check carefully before switching.

26.6"16" rim5.3"9.6" wide
245/55R16 (solid) compared with 245/65R16 (dashed outline), drawn to scale

With 245/65R16 tires, when your speedometer says 60 mph you are really going

64.3 mph

245/65R16 is +1.93 inches (+7.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/55R16245/65R16Difference%
Overall diameter26.61"28.54"+1.93"+7.2%
Section width9.65"9.65"0.00"0.0%
Sidewall height5.31"6.27"+0.96"+18.2%
Circumference83.60"89.66"+6.06"+7.2%
Revolutions per mile757.9706.7−51.2−6.8%

Speedometer difference

If your vehicle came with 245/55R16 and you fit 245/65R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.4 mph+1.4 mph
30 mph32.2 mph+2.2 mph
40 mph42.9 mph+2.9 mph
50 mph53.6 mph+3.6 mph
60 mph64.3 mph+4.3 mph
65 mph69.7 mph+4.7 mph
70 mph75.1 mph+5.1 mph
75 mph80.4 mph+5.4 mph
80 mph85.8 mph+5.8 mph

Each size on its own

Questions

Which is bigger, 245/55R16 or 245/65R16?
245/65R16 is taller by 1.93 inches (28.54" vs 26.61"). 245/55R16 is the same width.
Can I replace 245/55R16 with 245/65R16?
It is not recommended without checking carefully. The diameter difference is +7.2%, 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 245/65R16 change my speedometer?
When your speedometer reads 60 mph with 245/65R16 fitted (calibrated for 245/55R16), your real speed is 64.3 mph. Your odometer will under-count miles by about 7.2%.
Will 245/65R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.96 inches of ground clearance at the axle.

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