CarSpecsHQ

255/35R18 vs 265/30R19

265/30R19 is a safe swap for 255/35R18 by the usual ±3% rule: the diameter differs by +0.93%.

18" → 19"
255/35R18 25.03" · 265/30R19 25.26" · drawn to scale

Side by side

255/35R18265/30R19Difference
Overall diameter25.03"25.26"+0.23" (+0.93%)
Section width255 mm265 mm+10 mm
Sidewall3.51"3.13"-0.38"
Rim18"19"+1"
Circumference78.6"79.4"+0.7"
Revs per mile806798-7
Ride height——+0.12"
Speedometer reads 60 mph60.060.6+0.6 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.6 mph

With 265/30R19 on a car calibrated for 255/35R18, the speedometer reads 59.4 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 mph60.6 mph
70 mph70.6 mph
80 mph80.7 mph

Other sizes close to 255/35R18

Questions

Can I replace 255/35R18 with 265/30R19?

265/30R19 is a safe swap for 255/35R18 by the usual ±3% rule: the diameter differs by +0.93%.

What's the difference between 255/35R18 and 265/30R19?

265/30R19 is 0.23" taller and 10 mm wider; the sidewall is -0.38". At an indicated 60 mph you'd actually be doing 60.6 mph.

Will 265/30R19 fit on 255/35R18 wheels?

No — 255/35R18 needs a 18" wheel and 265/30R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.