CarSpecsHQ

215/45R18 vs 285/30R19

285/30R19 is a safe swap for 215/45R18 by the usual ±3% rule: the diameter differs by +0.45%.

18" → 19"
215/45R18 25.62" · 285/30R19 25.73" · drawn to scale

Side by side

215/45R18285/30R19Difference
Overall diameter25.62"25.73"+0.11" (+0.45%)
Section width215 mm285 mm+70 mm
Sidewall3.81"3.37"-0.44"
Rim18"19"+1"
Circumference80.5"80.8"+0.4"
Revs per mile787784-3
Ride height——+0.06"
Speedometer reads 60 mph60.060.3+0.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.3 mph

With 285/30R19 on a car calibrated for 215/45R18, the speedometer reads 59.7 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 mph60.3 mph
70 mph70.3 mph
80 mph80.4 mph

Other sizes close to 215/45R18

Questions

Can I replace 215/45R18 with 285/30R19?

285/30R19 is a safe swap for 215/45R18 by the usual ±3% rule: the diameter differs by +0.45%.

What's the difference between 215/45R18 and 285/30R19?

285/30R19 is 0.11" taller and 70 mm wider; the sidewall is -0.44". At an indicated 60 mph you'd actually be doing 60.3 mph.

Will 285/30R19 fit on 215/45R18 wheels?

No — 215/45R18 needs a 18" wheel and 285/30R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.