CarSpecsHQ

285/45R19 vs 295/40R20

295/40R20 is a safe swap for 285/45R19 by the usual ±3% rule: the diameter differs by +0.66%.

19" → 20"
285/45R19 29.10" · 295/40R20 29.29" · drawn to scale

Side by side

285/45R19295/40R20Difference
Overall diameter29.10"29.29"+0.19" (+0.66%)
Section width285 mm295 mm+10 mm
Sidewall5.05"4.65"-0.40"
Rim19"20"+1"
Circumference91.4"92.0"+0.6"
Revs per mile693689-5
Ride height——+0.10"
Speedometer reads 60 mph60.060.4+0.4 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.4 mph

With 295/40R20 on a car calibrated for 285/45R19, the speedometer reads 59.6 mph when you're really doing 60, and the odometer under-counts by 0.7%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.3 mph
60 mph60.4 mph
70 mph70.5 mph
80 mph80.5 mph

Other sizes close to 285/45R19

Questions

Can I replace 285/45R19 with 295/40R20?

295/40R20 is a safe swap for 285/45R19 by the usual ±3% rule: the diameter differs by +0.66%.

What's the difference between 285/45R19 and 295/40R20?

295/40R20 is 0.19" taller and 10 mm wider; the sidewall is -0.40". At an indicated 60 mph you'd actually be doing 60.4 mph.

Will 295/40R20 fit on 285/45R19 wheels?

No — 285/45R19 needs a 19" wheel and 295/40R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.