235/70R15 vs 235/75R15

235/75R15 is 0.9" taller than 235/70R15 (3.3%)

Diameter difference+3.31%diameter 27.95" → 28.88"
235/70R15235/75R15
235/70R15235/75R15Difference
Overall diameter27.95"28.88"+0.93"
Section width9.25"9.25"±0.00"
Sidewall height6.48"6.94"+0.46"
Circumference87.8"90.7"+2.9"
Revolutions per mile722698−23
Wheel diameter15"15"±0"

Speedometer

ShowsActualDiff
30 mph31.0 mph+1.0
45 mph46.5 mph+1.5
60 mph62.0 mph+2.0
70 mph72.3 mph+2.3
80 mph82.6 mph+2.6

Gear ratio to match

CurrentEquivalent
3.423.53
3.553.67
3.733.85
4.104.24

235/75R15 is 0.93" taller than 235/70R15, a +3.31% change in diameter. That is more than the 3% many tire shops use as a limit, so plan on recalibrating the speedometer and checking ABS and stability control.

Ground clearance changes by 0.46" (half the diameter change), and the tire needs 0.46" more room above it.

Both tires are the same width, 9.25".

Both fit a 15" wheel; the sidewall is 0.46" taller on 235/75R15.

Details: 235/70R15 in inches · 235/75R15 in inches · change sizes in the calculator

FAQ

What is the difference between 235/70R15 and 235/75R15?

235/75R15 is 0.93" taller (+3.31%) and 0.00" wider than 235/70R15.

Will 235/75R15 change my speedometer?

Yes, by +3.31%. When the speedometer shows 60 mph you would be going 62.0 mph.

Can I replace 235/70R15 with 235/75R15?

It is a +3.3% diameter change, larger than the common 3% guideline, so check clearance and plan to recalibrate.