Tire Size Box

295/35R17 vs 295/40R17

295/40R17 compared with 295/35R17

+4.6% diameter, 0.0" width

295/40R17 is 26.29" tall vs 25.13". More than the 3% rule of thumb, so check carefully before switching.

25.1"17" rim4.1"11.6" wide
295/35R17 (solid) compared with 295/40R17 (dashed outline), drawn to scale

With 295/40R17 tires, when your speedometer says 60 mph you are really going

62.8 mph

295/40R17 is +1.16 inches (+4.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/35R17295/40R17Difference%
Overall diameter25.13"26.29"+1.16"+4.6%
Section width11.61"11.61"0.00"0.0%
Sidewall height4.06"4.65"+0.58"+14.3%
Circumference78.95"82.60"+3.65"+4.6%
Revolutions per mile802.6767.1−35.5−4.4%

Speedometer difference

If your vehicle came with 295/35R17 and you fit 295/40R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.4 mph+1.4 mph
40 mph41.8 mph+1.8 mph
50 mph52.3 mph+2.3 mph
60 mph62.8 mph+2.8 mph
65 mph68.0 mph+3.0 mph
70 mph73.2 mph+3.2 mph
75 mph78.5 mph+3.5 mph
80 mph83.7 mph+3.7 mph

Each size on its own

Questions

Which is bigger, 295/35R17 or 295/40R17?
295/40R17 is taller by 1.16 inches (26.29" vs 25.13"). 295/35R17 is the same width.
Can I replace 295/35R17 with 295/40R17?
It is not recommended without checking carefully. The diameter difference is +4.6%, 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 295/40R17 change my speedometer?
When your speedometer reads 60 mph with 295/40R17 fitted (calibrated for 295/35R17), your real speed is 62.8 mph. Your odometer will under-count miles by about 4.6%.
Will 295/40R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.58 inches of ground clearance at the axle.

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