CarSpecsHQ

295/30R18 vs 255/30R19

255/30R19 is a safe swap for 295/30R18 by the usual ±3% rule: the diameter differs by +0.22%.

18" → 19"
295/30R18 24.97" · 255/30R19 25.02" · drawn to scale

Side by side

295/30R18255/30R19Difference
Overall diameter24.97"25.02"+0.06" (+0.22%)
Section width295 mm255 mm-40 mm
Sidewall3.48"3.01"-0.47"
Rim18"19"+1"
Circumference78.4"78.6"+0.2"
Revs per mile808806-2
Ride height——+0.03"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 255/30R19 on a car calibrated for 295/30R18, 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 295/30R18

Questions

Can I replace 295/30R18 with 255/30R19?

255/30R19 is a safe swap for 295/30R18 by the usual ±3% rule: the diameter differs by +0.22%.

What's the difference between 295/30R18 and 255/30R19?

255/30R19 is 0.06" taller and 40 mm narrower; the sidewall is -0.47". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 255/30R19 fit on 295/30R18 wheels?

No — 295/30R18 needs a 18" wheel and 255/30R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.