CarSpecsHQ

245/45R18 vs 285/35R19

285/35R19 is a safe swap for 245/45R18 by the usual ±3% rule: the diameter differs by +0.65%.

18" → 19"
245/45R18 26.68" · 285/35R19 26.85" · drawn to scale

Side by side

245/45R18285/35R19Difference
Overall diameter26.68"26.85"+0.17" (+0.65%)
Section width245 mm285 mm+40 mm
Sidewall4.34"3.93"-0.41"
Rim18"19"+1"
Circumference83.8"84.4"+0.5"
Revs per mile756751-5
Ride height——+0.09"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 285/35R19 on a car calibrated for 245/45R18, 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 mph70.5 mph
80 mph80.5 mph

Other sizes close to 245/45R18

Questions

Can I replace 245/45R18 with 285/35R19?

285/35R19 is a safe swap for 245/45R18 by the usual ±3% rule: the diameter differs by +0.65%.

What's the difference between 245/45R18 and 285/35R19?

285/35R19 is 0.17" taller and 40 mm wider; the sidewall is -0.41". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 285/35R19 fit on 245/45R18 wheels?

No — 245/45R18 needs a 18" wheel and 285/35R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.