CarSpecsHQ

235/55R18 vs 295/40R19

295/40R19 is a safe swap for 235/55R18 by the usual ±3% rule: the diameter differs by +0.41%.

18" → 19"
235/55R18 28.18" · 295/40R19 28.29" · drawn to scale

Side by side

235/55R18295/40R19Difference
Overall diameter28.18"28.29"+0.11" (+0.41%)
Section width235 mm295 mm+60 mm
Sidewall5.09"4.65"-0.44"
Rim18"19"+1"
Circumference88.5"88.9"+0.4"
Revs per mile716713-3
Ride height——+0.06"
Speedometer reads 60 mph60.060.2+0.2 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.2 mph

With 295/40R19 on a car calibrated for 235/55R18, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.4%.

Speedo showsActual speed
30 mph30.1 mph
45 mph45.2 mph
60 mph60.2 mph
70 mph70.3 mph
80 mph80.3 mph

Other sizes close to 235/55R18

Questions

Can I replace 235/55R18 with 295/40R19?

295/40R19 is a safe swap for 235/55R18 by the usual ±3% rule: the diameter differs by +0.41%.

What's the difference between 235/55R18 and 295/40R19?

295/40R19 is 0.11" taller and 60 mm wider; the sidewall is -0.44". At an indicated 60 mph you'd actually be doing 60.2 mph.

Will 295/40R19 fit on 235/55R18 wheels?

No — 235/55R18 needs a 18" wheel and 295/40R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.