255/45R20

About 255/45R20

Factory fitments for 255/45R20 include the Acura RDX, Audi Q5, Hyundai Ioniq 5, Hyundai Santa Fe — meaning replacement tires in this size see steady demand and broad brand availability. At 29.04″ overall diameter, 255/45R20 turns 695 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 45% aspect ratio gives it a low-profile sidewall that delivers sharp steering response but transmits road imperfections. The 20″ rim pairing is typical for luxury SUV and performance-oriented platforms, so compatible wheels are easy to source new or used. Going one step shorter to 245/45R20 drops diameter by 1.22%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 235/50R20 adds 0.75% diameter — also inside the safe window, with marginally taller ride height. If you are shopping for a direct replacement, any tire within roughly ±0.7″ of the 29.04″ stock diameter (about ±2% in percentage terms) will keep ABS, TPMS, and odometer readings inside the vehicle's designed tolerance.

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