CarSpecsHQ

175/65R14 vs 225/45R15

225/45R15 is a safe swap for 175/65R14 by the usual ±3% rule: the diameter differs by +0.07%.

14" → 15"
175/65R14 22.96" · 225/45R15 22.97" · drawn to scale

Side by side

175/65R14225/45R15Difference
Overall diameter22.96"22.97"+0.02" (+0.07%)
Section width175 mm225 mm+50 mm
Sidewall4.48"3.99"-0.49"
Rim14"15"+1"
Circumference72.1"72.2"+0.0"
Revs per mile879878-1
Ride height——+0.01"
Speedometer reads 60 mph60.060.0+0.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.0 mph

With 225/45R15 on a car calibrated for 175/65R14, the speedometer reads 60.0 mph when you're really doing 60, and the odometer under-counts by 0.1%.

Speedo showsActual speed
30 mph30.0 mph
45 mph45.0 mph
60 mph60.0 mph
70 mph70.0 mph
80 mph80.1 mph

Other sizes close to 175/65R14

Questions

Can I replace 175/65R14 with 225/45R15?

225/45R15 is a safe swap for 175/65R14 by the usual ±3% rule: the diameter differs by +0.07%.

What's the difference between 175/65R14 and 225/45R15?

225/45R15 is 0.02" taller and 50 mm wider; the sidewall is -0.49". At an indicated 60 mph you'd actually be doing 60.0 mph.

Will 225/45R15 fit on 175/65R14 wheels?

No — 175/65R14 needs a 14" wheel and 225/45R15 a 15" wheel. This is a plus/minus-size swap that changes wheels too.