CarSpecsHQ

295/40R19 vs 235/45R20

235/45R20 is a safe swap for 295/40R19 by the usual ±3% rule: the diameter differs by +0.13%.

19" → 20"
295/40R19 28.29" · 235/45R20 28.33" · drawn to scale

Side by side

295/40R19235/45R20Difference
Overall diameter28.29"28.33"+0.04" (+0.13%)
Section width295 mm235 mm-60 mm
Sidewall4.65"4.16"-0.48"
Rim19"20"+1"
Circumference88.9"89.0"+0.1"
Revs per mile713712-1
Ride height——+0.02"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 235/45R20 on a car calibrated for 295/40R19, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.1%.

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 295/40R19

Questions

Can I replace 295/40R19 with 235/45R20?

235/45R20 is a safe swap for 295/40R19 by the usual ±3% rule: the diameter differs by +0.13%.

What's the difference between 295/40R19 and 235/45R20?

235/45R20 is 0.04" taller and 60 mm narrower; the sidewall is -0.48". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 235/45R20 fit on 295/40R19 wheels?

No — 295/40R19 needs a 19" wheel and 235/45R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.