CarSpecsHQ

255/40R20 vs 295/40R19

295/40R19 is a safe swap for 255/40R20 by the usual ±3% rule: the diameter differs by +0.93%.

20" → 19"
255/40R20 28.03" · 295/40R19 28.29" · drawn to scale

Side by side

255/40R20295/40R19Difference
Overall diameter28.03"28.29"+0.26" (+0.93%)
Section width255 mm295 mm+40 mm
Sidewall4.02"4.65"+0.63"
Rim20"19"-1"
Circumference88.1"88.9"+0.8"
Revs per mile719713-7
Ride height——+0.13"
Speedometer reads 60 mph60.060.6+0.6 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.6 mph

With 295/40R19 on a car calibrated for 255/40R20, 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 255/40R20

Questions

Can I replace 255/40R20 with 295/40R19?

295/40R19 is a safe swap for 255/40R20 by the usual ±3% rule: the diameter differs by +0.93%.

What's the difference between 255/40R20 and 295/40R19?

295/40R19 is 0.26" taller and 40 mm wider; the sidewall is +0.63". At an indicated 60 mph you'd actually be doing 60.6 mph.

Will 295/40R19 fit on 255/40R20 wheels?

No — 255/40R20 needs a 20" wheel and 295/40R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.