CarSpecsHQ

315/30R22 vs 275/40R22

275/40R22 is outside the ±3% rule as a replacement for 315/30R22: the diameter differs by +4.15%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

22" rim
315/30R22 29.44" · 275/40R22 30.66" · drawn to scale

Side by side

315/30R22275/40R22Difference
Overall diameter29.44"30.66"+1.22" (+4.15%)
Section width315 mm275 mm-40 mm
Sidewall3.72"4.33"+0.61"
Rim22"22"same
Circumference92.5"96.3"+3.8"
Revs per mile685658-27
Ride height——+0.61"
Speedometer reads 60 mph60.062.5+2.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.5 mph

With 275/40R22 on a car calibrated for 315/30R22, the speedometer reads 57.6 mph when you're really doing 60, and the odometer under-counts by 4.1%.

Speedo showsActual speed
30 mph31.2 mph
45 mph46.9 mph
60 mph62.5 mph
70 mph72.9 mph
80 mph83.3 mph

Other sizes close to 315/30R22

Questions

Can I replace 315/30R22 with 275/40R22?

275/40R22 is outside the ±3% rule as a replacement for 315/30R22: the diameter differs by +4.15%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 315/30R22 and 275/40R22?

275/40R22 is 1.22" taller and 40 mm narrower; the sidewall is +0.61". At an indicated 60 mph you'd actually be doing 62.5 mph.

Will 275/40R22 fit on 315/30R22 wheels?

Both use a 22" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.