265/35R24 vs 265/40R24

265/40R24 compared with 265/35R24

+3.3% diameter, 0.0" width

265/40R24 is 32.35" tall vs 31.30". More than the 3% rule of thumb, so check carefully before switching.

31.3"24" rim3.7"10.4" wide
265/35R24 (solid) compared with 265/40R24 (dashed outline), drawn to scale

With 265/40R24 tires, when your speedometer says 60 mph you are really going

62.0 mph

265/40R24 is +1.04 inches (+3.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/35R24265/40R24Difference%
Overall diameter31.30"32.35"+1.04"+3.3%
Section width10.43"10.43"0.00"0.0%
Sidewall height3.65"4.17"+0.52"+14.3%
Circumference98.34"101.62"+3.28"+3.3%
Revolutions per mile644.3623.5−20.8−3.2%

Speedometer difference

If your vehicle came with 265/35R24 and you fit 265/40R24, 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 mph41.3 mph+1.3 mph
50 mph51.7 mph+1.7 mph
60 mph62.0 mph+2.0 mph
65 mph67.2 mph+2.2 mph
70 mph72.3 mph+2.3 mph
75 mph77.5 mph+2.5 mph
80 mph82.7 mph+2.7 mph

Each size on its own

Questions

Which is bigger, 265/35R24 or 265/40R24?
265/40R24 is taller by 1.04 inches (32.35" vs 31.30"). 265/35R24 is the same width.
Can I replace 265/35R24 with 265/40R24?
It is not recommended without checking carefully. The diameter difference is +3.3%, 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 265/40R24 change my speedometer?
When your speedometer reads 60 mph with 265/40R24 fitted (calibrated for 265/35R24), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.3%.
Will 265/40R24 lift my vehicle?
Ride height changes by half the diameter difference: +0.52 inches of ground clearance at the axle.

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