Tire Size Box

265/35R17 vs 265/40R17

265/40R17 compared with 265/35R17

+4.3% diameter, 0.0" width

265/40R17 is 25.35" tall vs 24.30". More than the 3% rule of thumb, so check carefully before switching.

24.3"17" rim3.7"10.4" wide
265/35R17 (solid) compared with 265/40R17 (dashed outline), drawn to scale

With 265/40R17 tires, when your speedometer says 60 mph you are really going

62.6 mph

265/40R17 is +1.04 inches (+4.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/35R17265/40R17Difference%
Overall diameter24.30"25.35"+1.04"+4.3%
Section width10.43"10.43"0.00"0.0%
Sidewall height3.65"4.17"+0.52"+14.3%
Circumference76.35"79.63"+3.28"+4.3%
Revolutions per mile829.9795.7−34.2−4.1%

Speedometer difference

If your vehicle came with 265/35R17 and you fit 265/40R17, 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 mph41.7 mph+1.7 mph
50 mph52.1 mph+2.1 mph
60 mph62.6 mph+2.6 mph
65 mph67.8 mph+2.8 mph
70 mph73.0 mph+3.0 mph
75 mph78.2 mph+3.2 mph
80 mph83.4 mph+3.4 mph

Each size on its own

Questions

Which is bigger, 265/35R17 or 265/40R17?
265/40R17 is taller by 1.04 inches (25.35" vs 24.30"). 265/35R17 is the same width.
Can I replace 265/35R17 with 265/40R17?
It is not recommended without checking carefully. The diameter difference is +4.3%, 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 265/40R17 change my speedometer?
When your speedometer reads 60 mph with 265/40R17 fitted (calibrated for 265/35R17), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.3%.
Will 265/40R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.52 inches of ground clearance at the axle.

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