Tire Size Box

225/35R17 vs 225/45R17

225/45R17 compared with 225/35R17

+7.6% diameter, 0.0" width

225/45R17 is 24.97" tall vs 23.20". More than the 3% rule of thumb, so check carefully before switching.

23.2"17" rim3.1"8.9" wide
225/35R17 (solid) compared with 225/45R17 (dashed outline), drawn to scale

With 225/45R17 tires, when your speedometer says 60 mph you are really going

64.6 mph

225/45R17 is +1.77 inches (+7.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/35R17225/45R17Difference%
Overall diameter23.20"24.97"+1.77"+7.6%
Section width8.86"8.86"0.00"0.0%
Sidewall height3.10"3.99"+0.89"+28.6%
Circumference72.89"78.45"+5.57"+7.6%
Revolutions per mile869.3807.6−61.7−7.1%

Speedometer difference

If your vehicle came with 225/35R17 and you fit 225/45R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.3 mph+2.3 mph
40 mph43.1 mph+3.1 mph
50 mph53.8 mph+3.8 mph
60 mph64.6 mph+4.6 mph
65 mph70.0 mph+5.0 mph
70 mph75.3 mph+5.3 mph
75 mph80.7 mph+5.7 mph
80 mph86.1 mph+6.1 mph

Each size on its own

Questions

Which is bigger, 225/35R17 or 225/45R17?
225/45R17 is taller by 1.77 inches (24.97" vs 23.20"). 225/35R17 is the same width.
Can I replace 225/35R17 with 225/45R17?
It is not recommended without checking carefully. The diameter difference is +7.6%, 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 225/45R17 change my speedometer?
When your speedometer reads 60 mph with 225/45R17 fitted (calibrated for 225/35R17), your real speed is 64.6 mph. Your odometer will under-count miles by about 7.6%.
Will 225/45R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.89 inches of ground clearance at the axle.

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