CarSpecsHQ

295/30R18 vs 295/35R18

295/35R18 is outside the ±3% rule as a replacement for 295/30R18: the diameter differs by +4.65%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

18" rim
295/30R18 24.97" · 295/35R18 26.13" · drawn to scale

Side by side

295/30R18295/35R18Difference
Overall diameter24.97"26.13"+1.16" (+4.65%)
Section width295 mm295 mm0 mm
Sidewall3.48"4.06"+0.58"
Rim18"18"same
Circumference78.4"82.1"+3.6"
Revs per mile808772-36
Ride height——+0.58"
Speedometer reads 60 mph60.062.8+2.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.8 mph

With 295/35R18 on a car calibrated for 295/30R18, the speedometer reads 57.3 mph when you're really doing 60, and the odometer under-counts by 4.7%.

Speedo showsActual speed
30 mph31.4 mph
45 mph47.1 mph
60 mph62.8 mph
70 mph73.3 mph
80 mph83.7 mph

Other sizes close to 295/30R18

Questions

Can I replace 295/30R18 with 295/35R18?

295/35R18 is outside the ±3% rule as a replacement for 295/30R18: the diameter differs by +4.65%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 295/30R18 and 295/35R18?

295/35R18 is 1.16" taller and 0 mm wider; the sidewall is +0.58". At an indicated 60 mph you'd actually be doing 62.8 mph.

Will 295/35R18 fit on 295/30R18 wheels?

Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.