Tire Size Box

235/65R13 vs 235/75R13

235/75R13 compared with 235/65R13

+7.4% diameter, 0.0" width

235/75R13 is 26.88" tall vs 25.03". More than the 3% rule of thumb, so check carefully before switching.

25.0"13" rim6.0"9.3" wide
235/65R13 (solid) compared with 235/75R13 (dashed outline), drawn to scale

With 235/75R13 tires, when your speedometer says 60 mph you are really going

64.4 mph

235/75R13 is +1.85 inches (+7.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

235/65R13235/75R13Difference%
Overall diameter25.03"26.88"+1.85"+7.4%
Section width9.25"9.25"0.00"0.0%
Sidewall height6.01"6.94"+0.93"+15.4%
Circumference78.63"84.44"+5.81"+7.4%
Revolutions per mile805.8750.4−55.5−6.9%

Speedometer difference

If your vehicle came with 235/65R13 and you fit 235/75R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.2 mph+2.2 mph
40 mph43.0 mph+3.0 mph
50 mph53.7 mph+3.7 mph
60 mph64.4 mph+4.4 mph
65 mph69.8 mph+4.8 mph
70 mph75.2 mph+5.2 mph
75 mph80.5 mph+5.5 mph
80 mph85.9 mph+5.9 mph

Each size on its own

Questions

Which is bigger, 235/65R13 or 235/75R13?
235/75R13 is taller by 1.85 inches (26.88" vs 25.03"). 235/65R13 is the same width.
Can I replace 235/65R13 with 235/75R13?
It is not recommended without checking carefully. The diameter difference is +7.4%, 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 235/75R13 change my speedometer?
When your speedometer reads 60 mph with 235/75R13 fitted (calibrated for 235/65R13), your real speed is 64.4 mph. Your odometer will under-count miles by about 7.4%.
Will 235/75R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.93 inches of ground clearance at the axle.

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