CarSpecsHQ

315/35R20 vs 295/40R20

295/40R20 is a safe swap for 315/35R20 by the usual ±3% rule: the diameter differs by +2.13%.

20" rim
315/35R20 28.68" · 295/40R20 29.29" · drawn to scale

Side by side

315/35R20295/40R20Difference
Overall diameter28.68"29.29"+0.61" (+2.13%)
Section width315 mm295 mm-20 mm
Sidewall4.34"4.65"+0.31"
Rim20"20"same
Circumference90.1"92.0"+1.9"
Revs per mile703689-15
Ride height——+0.31"
Speedometer reads 60 mph60.061.3+1.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.3 mph

With 295/40R20 on a car calibrated for 315/35R20, the speedometer reads 58.8 mph when you're really doing 60, and the odometer under-counts by 2.1%.

Speedo showsActual speed
30 mph30.6 mph
45 mph46.0 mph
60 mph61.3 mph
70 mph71.5 mph
80 mph81.7 mph

Other sizes close to 315/35R20

Questions

Can I replace 315/35R20 with 295/40R20?

295/40R20 is a safe swap for 315/35R20 by the usual ±3% rule: the diameter differs by +2.13%.

What's the difference between 315/35R20 and 295/40R20?

295/40R20 is 0.61" taller and 20 mm narrower; the sidewall is +0.31". At an indicated 60 mph you'd actually be doing 61.3 mph.

Will 295/40R20 fit on 315/35R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.