CarSpecsHQ

265/40R18 vs 275/35R19

275/35R19 is a safe swap for 265/40R18 by the usual ±3% rule: the diameter differs by +0.88%.

18" → 19"
265/40R18 26.35" · 275/35R19 26.58" · drawn to scale

Side by side

265/40R18275/35R19Difference
Overall diameter26.35"26.58"+0.23" (+0.88%)
Section width265 mm275 mm+10 mm
Sidewall4.17"3.79"-0.38"
Rim18"19"+1"
Circumference82.8"83.5"+0.7"
Revs per mile765759-7
Ride height——+0.12"
Speedometer reads 60 mph60.060.5+0.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.5 mph

With 275/35R19 on a car calibrated for 265/40R18, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.9%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.4 mph
60 mph60.5 mph
70 mph70.6 mph
80 mph80.7 mph

Other sizes close to 265/40R18

Questions

Can I replace 265/40R18 with 275/35R19?

275/35R19 is a safe swap for 265/40R18 by the usual ±3% rule: the diameter differs by +0.88%.

What's the difference between 265/40R18 and 275/35R19?

275/35R19 is 0.23" taller and 10 mm wider; the sidewall is -0.38". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 275/35R19 fit on 265/40R18 wheels?

No — 265/40R18 needs a 18" wheel and 275/35R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.