CarSpecsHQ

295/35R21 vs 265/45R20

265/45R20 is a safe swap for 295/35R21 by the usual ±3% rule: the diameter differs by +0.89%.

21" → 20"
295/35R21 29.13" · 265/45R20 29.39" · drawn to scale

Side by side

295/35R21265/45R20Difference
Overall diameter29.13"29.39"+0.26" (+0.89%)
Section width295 mm265 mm-30 mm
Sidewall4.06"4.69"+0.63"
Rim21"20"-1"
Circumference91.5"92.3"+0.8"
Revs per mile692686-6
Ride height——+0.13"
Speedometer reads 60 mph60.060.5+0.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.5 mph

With 265/45R20 on a car calibrated for 295/35R21, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.9%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.4 mph
60 mph60.5 mph
70 mph70.6 mph
80 mph80.7 mph

Other sizes close to 295/35R21

Questions

Can I replace 295/35R21 with 265/45R20?

265/45R20 is a safe swap for 295/35R21 by the usual ±3% rule: the diameter differs by +0.89%.

What's the difference between 295/35R21 and 265/45R20?

265/45R20 is 0.26" taller and 30 mm narrower; the sidewall is +0.63". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 265/45R20 fit on 295/35R21 wheels?

No — 295/35R21 needs a 21" wheel and 265/45R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.