Tire Size Box

315/35R22 vs 315/45R22

315/45R22 compared with 315/35R22

+8.1% diameter, 0.0" width

315/45R22 is 33.16" tall vs 30.68". More than the 3% rule of thumb, so check carefully before switching.

30.7"22" rim4.3"12.4" wide
315/35R22 (solid) compared with 315/45R22 (dashed outline), drawn to scale

With 315/45R22 tires, when your speedometer says 60 mph you are really going

64.9 mph

315/45R22 is +2.48 inches (+8.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

315/35R22315/45R22Difference%
Overall diameter30.68"33.16"+2.48"+8.1%
Section width12.40"12.40"0.00"0.0%
Sidewall height4.34"5.58"+1.24"+28.6%
Circumference96.39"104.18"+7.79"+8.1%
Revolutions per mile657.3608.2−49.2−7.5%

Speedometer difference

If your vehicle came with 315/35R22 and you fit 315/45R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.6 mph+1.6 mph
30 mph32.4 mph+2.4 mph
40 mph43.2 mph+3.2 mph
50 mph54.0 mph+4.0 mph
60 mph64.9 mph+4.9 mph
65 mph70.3 mph+5.3 mph
70 mph75.7 mph+5.7 mph
75 mph81.1 mph+6.1 mph
80 mph86.5 mph+6.5 mph

Each size on its own

Questions

Which is bigger, 315/35R22 or 315/45R22?
315/45R22 is taller by 2.48 inches (33.16" vs 30.68"). 315/35R22 is the same width.
Can I replace 315/35R22 with 315/45R22?
It is not recommended without checking carefully. The diameter difference is +8.1%, 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 315/45R22 change my speedometer?
When your speedometer reads 60 mph with 315/45R22 fitted (calibrated for 315/35R22), your real speed is 64.9 mph. Your odometer will under-count miles by about 8.1%.
Will 315/45R22 lift my vehicle?
Ride height changes by half the diameter difference: +1.24 inches of ground clearance at the axle.

Other comparisons