Tire Size Box

275/45R16 vs 275/55R16

275/55R16 compared with 275/45R16

+8.4% diameter, 0.0" width

275/55R16 is 27.91" tall vs 25.74". More than the 3% rule of thumb, so check carefully before switching.

25.7"16" rim4.9"10.8" wide
275/45R16 (solid) compared with 275/55R16 (dashed outline), drawn to scale

With 275/55R16 tires, when your speedometer says 60 mph you are really going

65.0 mph

275/55R16 is +2.17 inches (+8.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

275/45R16275/55R16Difference%
Overall diameter25.74"27.91"+2.17"+8.4%
Section width10.83"10.83"0.00"0.0%
Sidewall height4.87"5.95"+1.08"+22.2%
Circumference80.88"87.68"+6.80"+8.4%
Revolutions per mile783.4722.6−60.8−7.8%

Speedometer difference

If your vehicle came with 275/45R16 and you fit 275/55R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.7 mph+1.7 mph
30 mph32.5 mph+2.5 mph
40 mph43.4 mph+3.4 mph
50 mph54.2 mph+4.2 mph
60 mph65.0 mph+5.0 mph
65 mph70.5 mph+5.5 mph
70 mph75.9 mph+5.9 mph
75 mph81.3 mph+6.3 mph
80 mph86.7 mph+6.7 mph

Each size on its own

Questions

Which is bigger, 275/45R16 or 275/55R16?
275/55R16 is taller by 2.17 inches (27.91" vs 25.74"). 275/45R16 is the same width.
Can I replace 275/45R16 with 275/55R16?
It is not recommended without checking carefully. The diameter difference is +8.4%, 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 275/55R16 change my speedometer?
When your speedometer reads 60 mph with 275/55R16 fitted (calibrated for 275/45R16), your real speed is 65.0 mph. Your odometer will under-count miles by about 8.4%.
Will 275/55R16 lift my vehicle?
Ride height changes by half the diameter difference: +1.08 inches of ground clearance at the axle.

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