CarSpecsHQ

295/30R20 vs 255/35R20

255/35R20 is a safe swap for 295/30R20 by the usual ±3% rule: the diameter differs by +0.22%.

20" rim
295/30R20 26.97" · 255/35R20 27.03" · drawn to scale

Side by side

295/30R20255/35R20Difference
Overall diameter26.97"27.03"+0.06" (+0.22%)
Section width295 mm255 mm-40 mm
Sidewall3.48"3.51"+0.03"
Rim20"20"same
Circumference84.7"84.9"+0.2"
Revs per mile748746-2
Ride height——+0.03"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 255/35R20 on a car calibrated for 295/30R20, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.

Speedo showsActual speed
30 mph30.1 mph
45 mph45.1 mph
60 mph60.1 mph
70 mph70.2 mph
80 mph80.2 mph

Other sizes close to 295/30R20

Questions

Can I replace 295/30R20 with 255/35R20?

255/35R20 is a safe swap for 295/30R20 by the usual ±3% rule: the diameter differs by +0.22%.

What's the difference between 295/30R20 and 255/35R20?

255/35R20 is 0.06" taller and 40 mm narrower; the sidewall is +0.03". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 255/35R20 fit on 295/30R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 255 mm tire and the fender clearance.