Tire Size Box

295/35R18 vs 295/45R18

295/45R18 compared with 295/35R18

+8.9% diameter, 0.0" width

295/45R18 is 28.45" tall vs 26.13". More than the 3% rule of thumb, so check carefully before switching.

26.1"18" rim4.1"11.6" wide
295/35R18 (solid) compared with 295/45R18 (dashed outline), drawn to scale

With 295/45R18 tires, when your speedometer says 60 mph you are really going

65.3 mph

295/45R18 is +2.32 inches (+8.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/35R18295/45R18Difference%
Overall diameter26.13"28.45"+2.32"+8.9%
Section width11.61"11.61"0.00"0.0%
Sidewall height4.06"5.23"+1.16"+28.6%
Circumference82.09"89.39"+7.30"+8.9%
Revolutions per mile771.8708.8−63.0−8.2%

Speedometer difference

If your vehicle came with 295/35R18 and you fit 295/45R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.8 mph+1.8 mph
30 mph32.7 mph+2.7 mph
40 mph43.6 mph+3.6 mph
50 mph54.4 mph+4.4 mph
60 mph65.3 mph+5.3 mph
65 mph70.8 mph+5.8 mph
70 mph76.2 mph+6.2 mph
75 mph81.7 mph+6.7 mph
80 mph87.1 mph+7.1 mph

Each size on its own

Questions

Which is bigger, 295/35R18 or 295/45R18?
295/45R18 is taller by 2.32 inches (28.45" vs 26.13"). 295/35R18 is the same width.
Can I replace 295/35R18 with 295/45R18?
It is not recommended without checking carefully. The diameter difference is +8.9%, 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 295/45R18 change my speedometer?
When your speedometer reads 60 mph with 295/45R18 fitted (calibrated for 295/35R18), your real speed is 65.3 mph. Your odometer will under-count miles by about 8.9%.
Will 295/45R18 lift my vehicle?
Ride height changes by half the diameter difference: +1.16 inches of ground clearance at the axle.

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