Tire Size Box

265/40R22 vs 265/45R22

265/45R22 compared with 265/40R22

+3.4% diameter, 0.0" width

265/45R22 is 31.39" tall vs 30.35". More than the 3% rule of thumb, so check carefully before switching.

30.3"22" rim4.2"10.4" wide
265/40R22 (solid) compared with 265/45R22 (dashed outline), drawn to scale

With 265/45R22 tires, when your speedometer says 60 mph you are really going

62.1 mph

265/45R22 is +1.04 inches (+3.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/40R22265/45R22Difference%
Overall diameter30.35"31.39"+1.04"+3.4%
Section width10.43"10.43"0.00"0.0%
Sidewall height4.17"4.69"+0.52"+12.5%
Circumference95.34"98.61"+3.28"+3.4%
Revolutions per mile664.6642.5−22.1−3.3%

Speedometer difference

If your vehicle came with 265/40R22 and you fit 265/45R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.4 mph+1.4 mph
50 mph51.7 mph+1.7 mph
60 mph62.1 mph+2.1 mph
65 mph67.2 mph+2.2 mph
70 mph72.4 mph+2.4 mph
75 mph77.6 mph+2.6 mph
80 mph82.8 mph+2.8 mph

Each size on its own

Questions

Which is bigger, 265/40R22 or 265/45R22?
265/45R22 is taller by 1.04 inches (31.39" vs 30.35"). 265/40R22 is the same width.
Can I replace 265/40R22 with 265/45R22?
It is not recommended without checking carefully. The diameter difference is +3.4%, 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 265/45R22 change my speedometer?
When your speedometer reads 60 mph with 265/45R22 fitted (calibrated for 265/40R22), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.4%.
Will 265/45R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.52 inches of ground clearance at the axle.

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