CarSpecsHQ

275/35R18 vs 245/35R19

245/35R19 is a safe swap for 275/35R18 by the usual ±3% rule: the diameter differs by +0.68%.

18" → 19"
275/35R18 25.58" · 245/35R19 25.75" · drawn to scale

Side by side

275/35R18245/35R19Difference
Overall diameter25.58"25.75"+0.17" (+0.68%)
Section width275 mm245 mm-30 mm
Sidewall3.79"3.38"-0.41"
Rim18"19"+1"
Circumference80.4"80.9"+0.5"
Revs per mile788783-5
Ride height——+0.09"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 245/35R19 on a car calibrated for 275/35R18, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.

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 275/35R18

Questions

Can I replace 275/35R18 with 245/35R19?

245/35R19 is a safe swap for 275/35R18 by the usual ±3% rule: the diameter differs by +0.68%.

What's the difference between 275/35R18 and 245/35R19?

245/35R19 is 0.17" taller and 30 mm narrower; the sidewall is -0.41". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 245/35R19 fit on 275/35R18 wheels?

No — 275/35R18 needs a 18" wheel and 245/35R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.