Tire Size Box

265/45R16 vs 265/55R16

265/55R16 compared with 265/45R16

+8.2% diameter, 0.0" width

265/55R16 is 27.48" tall vs 25.39". More than the 3% rule of thumb, so check carefully before switching.

25.4"16" rim4.7"10.4" wide
265/45R16 (solid) compared with 265/55R16 (dashed outline), drawn to scale

With 265/55R16 tires, when your speedometer says 60 mph you are really going

64.9 mph

265/55R16 is +2.09 inches (+8.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/45R16265/55R16Difference%
Overall diameter25.39"27.48"+2.09"+8.2%
Section width10.43"10.43"0.00"0.0%
Sidewall height4.69"5.74"+1.04"+22.2%
Circumference79.76"86.32"+6.56"+8.2%
Revolutions per mile794.3734.0−60.3−7.6%

Speedometer difference

If your vehicle came with 265/45R16 and you fit 265/55R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.6 mph+1.6 mph
30 mph32.5 mph+2.5 mph
40 mph43.3 mph+3.3 mph
50 mph54.1 mph+4.1 mph
60 mph64.9 mph+4.9 mph
65 mph70.3 mph+5.3 mph
70 mph75.8 mph+5.8 mph
75 mph81.2 mph+6.2 mph
80 mph86.6 mph+6.6 mph

Each size on its own

Questions

Which is bigger, 265/45R16 or 265/55R16?
265/55R16 is taller by 2.09 inches (27.48" vs 25.39"). 265/45R16 is the same width.
Can I replace 265/45R16 with 265/55R16?
It is not recommended without checking carefully. The diameter difference is +8.2%, 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 265/55R16 change my speedometer?
When your speedometer reads 60 mph with 265/55R16 fitted (calibrated for 265/45R16), your real speed is 64.9 mph. Your odometer will under-count miles by about 8.2%.
Will 265/55R16 lift my vehicle?
Ride height changes by half the diameter difference: +1.04 inches of ground clearance at the axle.

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