Tire Size Box

195/45R17 vs 195/55R17

195/55R17 compared with 195/45R17

+6.4% diameter, 0.0" width

195/55R17 is 25.44" tall vs 23.91". More than the 3% rule of thumb, so check carefully before switching.

23.9"17" rim3.5"7.7" wide
195/45R17 (solid) compared with 195/55R17 (dashed outline), drawn to scale

With 195/55R17 tires, when your speedometer says 60 mph you are really going

63.9 mph

195/55R17 is +1.54 inches (+6.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

195/45R17195/55R17Difference%
Overall diameter23.91"25.44"+1.54"+6.4%
Section width7.68"7.68"0.00"0.0%
Sidewall height3.45"4.22"+0.77"+22.2%
Circumference75.11"79.94"+4.82"+6.4%
Revolutions per mile843.5792.6−50.9−6.0%

Speedometer difference

If your vehicle came with 195/45R17 and you fit 195/55R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.3 mph+1.3 mph
30 mph31.9 mph+1.9 mph
40 mph42.6 mph+2.6 mph
50 mph53.2 mph+3.2 mph
60 mph63.9 mph+3.9 mph
65 mph69.2 mph+4.2 mph
70 mph74.5 mph+4.5 mph
75 mph79.8 mph+4.8 mph
80 mph85.1 mph+5.1 mph

Each size on its own

Questions

Which is bigger, 195/45R17 or 195/55R17?
195/55R17 is taller by 1.54 inches (25.44" vs 23.91"). 195/45R17 is the same width.
Can I replace 195/45R17 with 195/55R17?
It is not recommended without checking carefully. The diameter difference is +6.4%, 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 195/55R17 change my speedometer?
When your speedometer reads 60 mph with 195/55R17 fitted (calibrated for 195/45R17), your real speed is 63.9 mph. Your odometer will under-count miles by about 6.4%.
Will 195/55R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.77 inches of ground clearance at the axle.

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