Tire Size Box

225/45R19 vs 225/55R19

225/55R19 compared with 225/45R19

+6.6% diameter, 0.0" width

225/55R19 is 28.74" tall vs 26.97". More than the 3% rule of thumb, so check carefully before switching.

27.0"19" rim4.0"8.9" wide
225/45R19 (solid) compared with 225/55R19 (dashed outline), drawn to scale

With 225/55R19 tires, when your speedometer says 60 mph you are really going

63.9 mph

225/55R19 is +1.77 inches (+6.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/45R19225/55R19Difference%
Overall diameter26.97"28.74"+1.77"+6.6%
Section width8.86"8.86"0.00"0.0%
Sidewall height3.99"4.87"+0.89"+22.2%
Circumference84.74"90.30"+5.57"+6.6%
Revolutions per mile747.7701.6−46.1−6.2%

Speedometer difference

If your vehicle came with 225/45R19 and you fit 225/55R19, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.3 mph+1.3 mph
30 mph32.0 mph+2.0 mph
40 mph42.6 mph+2.6 mph
50 mph53.3 mph+3.3 mph
60 mph63.9 mph+3.9 mph
65 mph69.3 mph+4.3 mph
70 mph74.6 mph+4.6 mph
75 mph79.9 mph+4.9 mph
80 mph85.3 mph+5.3 mph

Each size on its own

Questions

Which is bigger, 225/45R19 or 225/55R19?
225/55R19 is taller by 1.77 inches (28.74" vs 26.97"). 225/45R19 is the same width.
Can I replace 225/45R19 with 225/55R19?
It is not recommended without checking carefully. The diameter difference is +6.6%, 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 225/55R19 change my speedometer?
When your speedometer reads 60 mph with 225/55R19 fitted (calibrated for 225/45R19), your real speed is 63.9 mph. Your odometer will under-count miles by about 6.6%.
Will 225/55R19 lift my vehicle?
Ride height changes by half the diameter difference: +0.89 inches of ground clearance at the axle.

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