Tire Size Box

355/35R19 vs 355/45R19

355/45R19 compared with 355/35R19

+9.7% diameter, 0.0" width

355/45R19 is 31.58" tall vs 28.78". More than the 3% rule of thumb, so check carefully before switching.

28.8"19" rim4.9"14.0" wide
355/35R19 (solid) compared with 355/45R19 (dashed outline), drawn to scale

With 355/45R19 tires, when your speedometer says 60 mph you are really going

65.8 mph

355/45R19 is +2.80 inches (+9.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

355/35R19355/45R19Difference%
Overall diameter28.78"31.58"+2.80"+9.7%
Section width13.98"13.98"0.00"0.0%
Sidewall height4.89"6.29"+1.40"+28.6%
Circumference90.43"99.21"+8.78"+9.7%
Revolutions per mile700.7638.7−62.0−8.9%

Speedometer difference

If your vehicle came with 355/35R19 and you fit 355/45R19, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.9 mph+1.9 mph
30 mph32.9 mph+2.9 mph
40 mph43.9 mph+3.9 mph
50 mph54.9 mph+4.9 mph
60 mph65.8 mph+5.8 mph
65 mph71.3 mph+6.3 mph
70 mph76.8 mph+6.8 mph
75 mph82.3 mph+7.3 mph
80 mph87.8 mph+7.8 mph

Each size on its own

Questions

Which is bigger, 355/35R19 or 355/45R19?
355/45R19 is taller by 2.80 inches (31.58" vs 28.78"). 355/35R19 is the same width.
Can I replace 355/35R19 with 355/45R19?
It is not recommended without checking carefully. The diameter difference is +9.7%, 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 355/45R19 change my speedometer?
When your speedometer reads 60 mph with 355/45R19 fitted (calibrated for 355/35R19), your real speed is 65.8 mph. Your odometer will under-count miles by about 9.7%.
Will 355/45R19 lift my vehicle?
Ride height changes by half the diameter difference: +1.40 inches of ground clearance at the axle.

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