Tire Size Box

215/80R15 vs 235/80R15

235/80R15 compared with 215/80R15

+4.4% diameter, +0.8" width

235/80R15 is 29.80" tall vs 28.54". More than the 3% rule of thumb, so check carefully before switching.

28.5"15" rim6.8"8.5" wide
215/80R15 (solid) compared with 235/80R15 (dashed outline), drawn to scale

With 235/80R15 tires, when your speedometer says 60 mph you are really going

62.6 mph

235/80R15 is +1.26 inches (+4.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

215/80R15235/80R15Difference%
Overall diameter28.54"29.80"+1.26"+4.4%
Section width8.46"9.25"+0.79"+9.3%
Sidewall height6.77"7.40"+0.63"+9.3%
Circumference89.67"93.63"+3.96"+4.4%
Revolutions per mile706.6676.7−29.9−4.2%

Speedometer difference

If your vehicle came with 215/80R15 and you fit 235/80R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.3 mph+1.3 mph
40 mph41.8 mph+1.8 mph
50 mph52.2 mph+2.2 mph
60 mph62.6 mph+2.6 mph
65 mph67.9 mph+2.9 mph
70 mph73.1 mph+3.1 mph
75 mph78.3 mph+3.3 mph
80 mph83.5 mph+3.5 mph

Each size on its own

Questions

Which is bigger, 215/80R15 or 235/80R15?
235/80R15 is taller by 1.26 inches (29.80" vs 28.54"). 235/80R15 is wider by 0.79 inches.
Can I replace 215/80R15 with 235/80R15?
It is not recommended without checking carefully. The diameter difference is +4.4%, 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 235/80R15 change my speedometer?
When your speedometer reads 60 mph with 235/80R15 fitted (calibrated for 215/80R15), your real speed is 62.6 mph. Your odometer will under-count miles by about 4.4%.
Will 235/80R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.63 inches of ground clearance at the axle.

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