CarSpecsHQ

265/65R18 vs 265/70R18

265/70R18 is outside the ±3% rule as a replacement for 265/65R18: the diameter differs by +3.31%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

18" rim
265/65R18 31.56" · 265/70R18 32.61" · drawn to scale

Side by side

265/65R18265/70R18Difference
Overall diameter31.56"32.61"+1.04" (+3.31%)
Section width265 mm265 mm0 mm
Sidewall6.78"7.30"+0.52"
Rim18"18"same
Circumference99.2"102.4"+3.3"
Revs per mile639619-20
Ride height——+0.52"
Speedometer reads 60 mph60.062.0+2.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.0 mph

With 265/70R18 on a car calibrated for 265/65R18, the speedometer reads 58.1 mph when you're really doing 60, and the odometer under-counts by 3.3%.

Speedo showsActual speed
30 mph31.0 mph
45 mph46.5 mph
60 mph62.0 mph
70 mph72.3 mph
80 mph82.6 mph

Other sizes close to 265/65R18

Questions

Can I replace 265/65R18 with 265/70R18?

265/70R18 is outside the ±3% rule as a replacement for 265/65R18: the diameter differs by +3.31%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 265/65R18 and 265/70R18?

265/70R18 is 1.04" taller and 0 mm wider; the sidewall is +0.52". At an indicated 60 mph you'd actually be doing 62.0 mph.

Will 265/70R18 fit on 265/65R18 wheels?

Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 265 mm tire and the fender clearance.