CarSpecsHQ

245/35R19 vs 285/35R18

285/35R18 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +0.40%.

19" → 18"
245/35R19 25.75" · 285/35R18 25.85" · drawn to scale

Side by side

245/35R19285/35R18Difference
Overall diameter25.75"25.85"+0.10" (+0.40%)
Section width245 mm285 mm+40 mm
Sidewall3.38"3.93"+0.55"
Rim19"18"-1"
Circumference80.9"81.2"+0.3"
Revs per mile783780-3
Ride height——+0.05"
Speedometer reads 60 mph60.060.2+0.2 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.2 mph

With 285/35R18 on a car calibrated for 245/35R19, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.4%.

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

Other sizes close to 245/35R19

Questions

Can I replace 245/35R19 with 285/35R18?

285/35R18 is a safe swap for 245/35R19 by the usual ±3% rule: the diameter differs by +0.40%.

What's the difference between 245/35R19 and 285/35R18?

285/35R18 is 0.10" taller and 40 mm wider; the sidewall is +0.55". At an indicated 60 mph you'd actually be doing 60.2 mph.

Will 285/35R18 fit on 245/35R19 wheels?

No — 245/35R19 needs a 19" wheel and 285/35R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.