CarSpecsHQ

235/55R19 vs 295/40R20

295/40R20 is a safe swap for 235/55R19 by the usual ±3% rule: the diameter differs by +0.39%.

19" → 20"
235/55R19 29.18" · 295/40R20 29.29" · drawn to scale

Side by side

235/55R19295/40R20Difference
Overall diameter29.18"29.29"+0.11" (+0.39%)
Section width235 mm295 mm+60 mm
Sidewall5.09"4.65"-0.44"
Rim19"20"+1"
Circumference91.7"92.0"+0.4"
Revs per mile691689-3
Ride height——+0.06"
Speedometer reads 60 mph60.060.2+0.2 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.2 mph

With 295/40R20 on a car calibrated for 235/55R19, 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 235/55R19

Questions

Can I replace 235/55R19 with 295/40R20?

295/40R20 is a safe swap for 235/55R19 by the usual ±3% rule: the diameter differs by +0.39%.

What's the difference between 235/55R19 and 295/40R20?

295/40R20 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 295/40R20 fit on 235/55R19 wheels?

No — 235/55R19 needs a 19" wheel and 295/40R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.