CarSpecsHQ

295/40R20 vs 275/45R20

275/45R20 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +1.55%.

20" rim
295/40R20 29.29" · 275/45R20 29.74" · drawn to scale

Side by side

295/40R20275/45R20Difference
Overall diameter29.29"29.74"+0.45" (+1.55%)
Section width295 mm275 mm-20 mm
Sidewall4.65"4.87"+0.23"
Rim20"20"same
Circumference92.0"93.4"+1.4"
Revs per mile689678-10
Ride height——+0.23"
Speedometer reads 60 mph60.060.9+0.9 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.9 mph

With 275/45R20 on a car calibrated for 295/40R20, the speedometer reads 59.1 mph when you're really doing 60, and the odometer under-counts by 1.5%.

Speedo showsActual speed
30 mph30.5 mph
45 mph45.7 mph
60 mph60.9 mph
70 mph71.1 mph
80 mph81.2 mph

Other sizes close to 295/40R20

Questions

Can I replace 295/40R20 with 275/45R20?

275/45R20 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +1.55%.

What's the difference between 295/40R20 and 275/45R20?

275/45R20 is 0.45" taller and 20 mm narrower; the sidewall is +0.23". At an indicated 60 mph you'd actually be doing 60.9 mph.

Will 275/45R20 fit on 295/40R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.