CarSpecsHQ

315/30R20 vs 295/35R20

295/35R20 is a safe swap for 315/30R20 by the usual ±3% rule: the diameter differs by +2.51%.

20" rim
315/30R20 27.44" · 295/35R20 28.13" · drawn to scale

Side by side

315/30R20295/35R20Difference
Overall diameter27.44"28.13"+0.69" (+2.51%)
Section width315 mm295 mm-20 mm
Sidewall3.72"4.06"+0.34"
Rim20"20"same
Circumference86.2"88.4"+2.2"
Revs per mile735717-18
Ride height——+0.34"
Speedometer reads 60 mph60.061.5+1.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.5 mph

With 295/35R20 on a car calibrated for 315/30R20, the speedometer reads 58.5 mph when you're really doing 60, and the odometer under-counts by 2.5%.

Speedo showsActual speed
30 mph30.8 mph
45 mph46.1 mph
60 mph61.5 mph
70 mph71.8 mph
80 mph82.0 mph

Other sizes close to 315/30R20

Questions

Can I replace 315/30R20 with 295/35R20?

295/35R20 is a safe swap for 315/30R20 by the usual ±3% rule: the diameter differs by +2.51%.

What's the difference between 315/30R20 and 295/35R20?

295/35R20 is 0.69" taller and 20 mm narrower; the sidewall is +0.34". At an indicated 60 mph you'd actually be doing 61.5 mph.

Will 295/35R20 fit on 315/30R20 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.