Tire Size Box

275/45R19 vs 275/55R19

275/55R19 compared with 275/45R19

+7.5% diameter, 0.0" width

275/55R19 is 30.91" tall vs 28.74". More than the 3% rule of thumb, so check carefully before switching.

28.7"19" rim4.9"10.8" wide
275/45R19 (solid) compared with 275/55R19 (dashed outline), drawn to scale

With 275/55R19 tires, when your speedometer says 60 mph you are really going

64.5 mph

275/55R19 is +2.17 inches (+7.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

275/45R19275/55R19Difference%
Overall diameter28.74"30.91"+2.17"+7.5%
Section width10.83"10.83"0.00"0.0%
Sidewall height4.87"5.95"+1.08"+22.2%
Circumference90.30"97.10"+6.80"+7.5%
Revolutions per mile701.6652.5−49.2−7.0%

Speedometer difference

If your vehicle came with 275/45R19 and you fit 275/55R19, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.3 mph+2.3 mph
40 mph43.0 mph+3.0 mph
50 mph53.8 mph+3.8 mph
60 mph64.5 mph+4.5 mph
65 mph69.9 mph+4.9 mph
70 mph75.3 mph+5.3 mph
75 mph80.6 mph+5.6 mph
80 mph86.0 mph+6.0 mph

Each size on its own

Questions

Which is bigger, 275/45R19 or 275/55R19?
275/55R19 is taller by 2.17 inches (30.91" vs 28.74"). 275/45R19 is the same width.
Can I replace 275/45R19 with 275/55R19?
It is not recommended without checking carefully. The diameter difference is +7.5%, 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 275/55R19 change my speedometer?
When your speedometer reads 60 mph with 275/55R19 fitted (calibrated for 275/45R19), your real speed is 64.5 mph. Your odometer will under-count miles by about 7.5%.
Will 275/55R19 lift my vehicle?
Ride height changes by half the diameter difference: +1.08 inches of ground clearance at the axle.

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