Tire Size Box

355/35R22 vs 355/40R22

355/40R22 compared with 355/35R22

+4.4% diameter, 0.0" width

355/40R22 is 33.18" tall vs 31.78". More than the 3% rule of thumb, so check carefully before switching.

31.8"22" rim4.9"14.0" wide
355/35R22 (solid) compared with 355/40R22 (dashed outline), drawn to scale

With 355/40R22 tires, when your speedometer says 60 mph you are really going

62.6 mph

355/40R22 is +1.40 inches (+4.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

355/35R22355/40R22Difference%
Overall diameter31.78"33.18"+1.40"+4.4%
Section width13.98"13.98"0.00"0.0%
Sidewall height4.89"5.59"+0.70"+14.3%
Circumference99.85"104.24"+4.39"+4.4%
Revolutions per mile634.5607.8−26.7−4.2%

Speedometer difference

If your vehicle came with 355/35R22 and you fit 355/40R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.3 mph+1.3 mph
40 mph41.8 mph+1.8 mph
50 mph52.2 mph+2.2 mph
60 mph62.6 mph+2.6 mph
65 mph67.9 mph+2.9 mph
70 mph73.1 mph+3.1 mph
75 mph78.3 mph+3.3 mph
80 mph83.5 mph+3.5 mph

Each size on its own

Questions

Which is bigger, 355/35R22 or 355/40R22?
355/40R22 is taller by 1.40 inches (33.18" vs 31.78"). 355/35R22 is the same width.
Can I replace 355/35R22 with 355/40R22?
It is not recommended without checking carefully. The diameter difference is +4.4%, 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 355/40R22 change my speedometer?
When your speedometer reads 60 mph with 355/40R22 fitted (calibrated for 355/35R22), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.4%.
Will 355/40R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.70 inches of ground clearance at the axle.

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