CarSpecsHQ

265/70R18 vs 285/70R17

285/70R17 is a safe swap for 265/70R18 by the usual ±3% rule: the diameter differs by +0.31%.

18" → 17"
265/70R18 32.61" · 285/70R17 32.71" · drawn to scale

Side by side

265/70R18285/70R17Difference
Overall diameter32.61"32.71"+0.10" (+0.31%)
Section width265 mm285 mm+20 mm
Sidewall7.30"7.85"+0.55"
Rim18"17"-1"
Circumference102.4"102.8"+0.3"
Revs per mile619617-2
Ride height——+0.05"
Speedometer reads 60 mph60.060.2+0.2 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.2 mph

With 285/70R17 on a car calibrated for 265/70R18, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.3%.

Speedo showsActual speed
30 mph30.1 mph
45 mph45.1 mph
60 mph60.2 mph
70 mph70.2 mph
80 mph80.3 mph

Other sizes close to 265/70R18

Questions

Can I replace 265/70R18 with 285/70R17?

285/70R17 is a safe swap for 265/70R18 by the usual ±3% rule: the diameter differs by +0.31%.

What's the difference between 265/70R18 and 285/70R17?

285/70R17 is 0.10" taller and 20 mm wider; the sidewall is +0.55". At an indicated 60 mph you'd actually be doing 60.2 mph.

Will 285/70R17 fit on 265/70R18 wheels?

No — 265/70R18 needs a 18" wheel and 285/70R17 a 17" wheel. This is a plus/minus-size swap that changes wheels too.