CarSpecsHQ

265/70R18 vs 33x12.50R18

33x12.50R18 is a safe swap for 265/70R18 by the usual ±3% rule: the diameter differs by +1.21%.

18" rim
265/70R18 32.61" · 33x12.50R18 33.00" · drawn to scale

Side by side

265/70R1833x12.50R18Difference
Overall diameter32.61"33.00"+0.39" (+1.21%)
Section width265 mm318 mm+53 mm
Sidewall7.30"7.50"+0.20"
Rim18"18"same
Circumference102.4"103.7"+1.2"
Revs per mile619611-7
Ride height——+0.20"
Speedometer reads 60 mph60.060.7+0.7 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.7 mph

With 33x12.50R18 on a car calibrated for 265/70R18, the speedometer reads 59.3 mph when you're really doing 60, and the odometer under-counts by 1.2%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.5 mph
60 mph60.7 mph
70 mph70.8 mph
80 mph81.0 mph

Other sizes close to 265/70R18

Questions

Can I replace 265/70R18 with 33x12.50R18?

33x12.50R18 is a safe swap for 265/70R18 by the usual ±3% rule: the diameter differs by +1.21%.

What's the difference between 265/70R18 and 33x12.50R18?

33x12.50R18 is 0.39" taller and 53 mm wider; the sidewall is +0.20". At an indicated 60 mph you'd actually be doing 60.7 mph.

Will 33x12.50R18 fit on 265/70R18 wheels?

Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 318 mm tire and the fender clearance.