CarSpecsHQ

265/35R19 vs 235/45R18

235/45R18 is a safe swap for 265/35R19 by the usual ±3% rule: the diameter differs by +0.09%.

19" → 18"
265/35R19 26.30" · 235/45R18 26.33" · drawn to scale

Side by side

265/35R19235/45R18Difference
Overall diameter26.30"26.33"+0.02" (+0.09%)
Section width265 mm235 mm-30 mm
Sidewall3.65"4.16"+0.51"
Rim19"18"-1"
Circumference82.6"82.7"+0.1"
Revs per mile767766-1
Ride height——+0.01"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 235/45R18 on a car calibrated for 265/35R19, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.1%.

Speedo showsActual speed
30 mph30.0 mph
45 mph45.0 mph
60 mph60.1 mph
70 mph70.1 mph
80 mph80.1 mph

Other sizes close to 265/35R19

Questions

Can I replace 265/35R19 with 235/45R18?

235/45R18 is a safe swap for 265/35R19 by the usual ±3% rule: the diameter differs by +0.09%.

What's the difference between 265/35R19 and 235/45R18?

235/45R18 is 0.02" taller and 30 mm narrower; the sidewall is +0.51". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 235/45R18 fit on 265/35R19 wheels?

No — 265/35R19 needs a 19" wheel and 235/45R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.