Tire Size Box

345/35R22 vs 345/45R22

345/45R22 compared with 345/35R22

+8.6% diameter, 0.0" width

345/45R22 is 34.22" tall vs 31.51". More than the 3% rule of thumb, so check carefully before switching.

31.5"22" rim4.8"13.6" wide
345/35R22 (solid) compared with 345/45R22 (dashed outline), drawn to scale

With 345/45R22 tires, when your speedometer says 60 mph you are really going

65.2 mph

345/45R22 is +2.72 inches (+8.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

345/35R22345/45R22Difference%
Overall diameter31.51"34.22"+2.72"+8.6%
Section width13.58"13.58"0.00"0.0%
Sidewall height4.75"6.11"+1.36"+28.6%
Circumference98.98"107.52"+8.53"+8.6%
Revolutions per mile640.1589.3−50.8−7.9%

Speedometer difference

If your vehicle came with 345/35R22 and you fit 345/45R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.7 mph+1.7 mph
30 mph32.6 mph+2.6 mph
40 mph43.4 mph+3.4 mph
50 mph54.3 mph+4.3 mph
60 mph65.2 mph+5.2 mph
65 mph70.6 mph+5.6 mph
70 mph76.0 mph+6.0 mph
75 mph81.5 mph+6.5 mph
80 mph86.9 mph+6.9 mph

Each size on its own

Questions

Which is bigger, 345/35R22 or 345/45R22?
345/45R22 is taller by 2.72 inches (34.22" vs 31.51"). 345/35R22 is the same width.
Can I replace 345/35R22 with 345/45R22?
It is not recommended without checking carefully. The diameter difference is +8.6%, 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 345/45R22 change my speedometer?
When your speedometer reads 60 mph with 345/45R22 fitted (calibrated for 345/35R22), your real speed is 65.2 mph. Your odometer will under-count miles by about 8.6%.
Will 345/45R22 lift my vehicle?
Ride height changes by half the diameter difference: +1.36 inches of ground clearance at the axle.

Other comparisons