CarSpecsHQ

235/75R15 vs 255/65R16

255/65R16 is a safe swap for 235/75R15 by the usual ±3% rule: the diameter differs by +0.60%.

15" → 16"
235/75R15 28.88" · 255/65R16 29.05" · drawn to scale

Side by side

235/75R15255/65R16Difference
Overall diameter28.88"29.05"+0.17" (+0.60%)
Section width235 mm255 mm+20 mm
Sidewall6.94"6.53"-0.41"
Rim15"16"+1"
Circumference90.7"91.3"+0.5"
Revs per mile698694-4
Ride height——+0.09"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 255/65R16 on a car calibrated for 235/75R15, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.6%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.3 mph
60 mph60.4 mph
70 mph70.4 mph
80 mph80.5 mph

Other sizes close to 235/75R15

Questions

Can I replace 235/75R15 with 255/65R16?

255/65R16 is a safe swap for 235/75R15 by the usual ±3% rule: the diameter differs by +0.60%.

What's the difference between 235/75R15 and 255/65R16?

255/65R16 is 0.17" taller and 20 mm wider; the sidewall is -0.41". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 255/65R16 fit on 235/75R15 wheels?

No — 235/75R15 needs a 15" wheel and 255/65R16 a 16" wheel. This is a plus/minus-size swap that changes wheels too.