Tire Size Box

215/55R17 vs 235/55R17

235/55R17 compared with 215/55R17

+3.3% diameter, +0.8" width

235/55R17 is 27.18" tall vs 26.31". More than the 3% rule of thumb, so check carefully before switching.

26.3"17" rim4.7"8.5" wide
215/55R17 (solid) compared with 235/55R17 (dashed outline), drawn to scale

With 235/55R17 tires, when your speedometer says 60 mph you are really going

62.0 mph

235/55R17 is +0.87 inches (+3.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

215/55R17235/55R17Difference%
Overall diameter26.31"27.18"+0.87"+3.3%
Section width8.46"9.25"+0.79"+9.3%
Sidewall height4.66"5.09"+0.43"+9.3%
Circumference82.66"85.38"+2.72"+3.3%
Revolutions per mile766.5742.1−24.4−3.2%

Speedometer difference

If your vehicle came with 215/55R17 and you fit 235/55R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.6 mph+1.6 mph
60 mph62.0 mph+2.0 mph
65 mph67.1 mph+2.1 mph
70 mph72.3 mph+2.3 mph
75 mph77.5 mph+2.5 mph
80 mph82.6 mph+2.6 mph

Each size on its own

Questions

Which is bigger, 215/55R17 or 235/55R17?
235/55R17 is taller by 0.87 inches (27.18" vs 26.31"). 235/55R17 is wider by 0.79 inches.
Can I replace 215/55R17 with 235/55R17?
It is not recommended without checking carefully. The diameter difference is +3.3%, 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 235/55R17 change my speedometer?
When your speedometer reads 60 mph with 235/55R17 fitted (calibrated for 215/55R17), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.3%.
Will 235/55R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.43 inches of ground clearance at the axle.

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