Tire Size Box

265/40R19 vs 265/50R19

265/50R19 compared with 265/40R19

+7.6% diameter, 0.0" width

265/50R19 is 29.43" tall vs 27.35". More than the 3% rule of thumb, so check carefully before switching.

27.3"19" rim4.2"10.4" wide
265/40R19 (solid) compared with 265/50R19 (dashed outline), drawn to scale

With 265/50R19 tires, when your speedometer says 60 mph you are really going

64.6 mph

265/50R19 is +2.09 inches (+7.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/40R19265/50R19Difference%
Overall diameter27.35"29.43"+2.09"+7.6%
Section width10.43"10.43"0.00"0.0%
Sidewall height4.17"5.22"+1.04"+25.0%
Circumference85.91"92.47"+6.56"+7.6%
Revolutions per mile737.5685.2−52.3−7.1%

Speedometer difference

If your vehicle came with 265/40R19 and you fit 265/50R19, 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 mph43.1 mph+3.1 mph
50 mph53.8 mph+3.8 mph
60 mph64.6 mph+4.6 mph
65 mph70.0 mph+5.0 mph
70 mph75.3 mph+5.3 mph
75 mph80.7 mph+5.7 mph
80 mph86.1 mph+6.1 mph

Each size on its own

Questions

Which is bigger, 265/40R19 or 265/50R19?
265/50R19 is taller by 2.09 inches (29.43" vs 27.35"). 265/40R19 is the same width.
Can I replace 265/40R19 with 265/50R19?
It is not recommended without checking carefully. The diameter difference is +7.6%, 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 265/50R19 change my speedometer?
When your speedometer reads 60 mph with 265/50R19 fitted (calibrated for 265/40R19), your real speed is 64.6 mph. Your odometer will under-count miles by about 7.6%.
Will 265/50R19 lift my vehicle?
Ride height changes by half the diameter difference: +1.04 inches of ground clearance at the axle.

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