CarSpecsHQ

265/35R19 vs 265/40R18

265/40R18 is a safe swap for 265/35R19 by the usual ±3% rule: the diameter differs by +0.16%.

19" → 18"
265/35R19 26.30" · 265/40R18 26.35" · drawn to scale

Side by side

265/35R19265/40R18Difference
Overall diameter26.30"26.35"+0.04" (+0.16%)
Section width265 mm265 mm0 mm
Sidewall3.65"4.17"+0.52"
Rim19"18"-1"
Circumference82.6"82.8"+0.1"
Revs per mile767765-1
Ride height——+0.02"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 265/40R18 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 0.2%.

Speedo showsActual speed
30 mph30.0 mph
45 mph45.1 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 265/40R18?

265/40R18 is a safe swap for 265/35R19 by the usual ±3% rule: the diameter differs by +0.16%.

What's the difference between 265/35R19 and 265/40R18?

265/40R18 is 0.04" taller and 0 mm wider; the sidewall is +0.52". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 265/40R18 fit on 265/35R19 wheels?

No — 265/35R19 needs a 19" wheel and 265/40R18 a 18" wheel. This is a plus/minus-size swap that changes wheels too.