235/55R20

About 235/55R20

Factory fitments for 235/55R20 include the Cadillac XT5, Cadillac XT6, GMC Acadia — meaning replacement tires in this size see steady demand and broad brand availability. At 30.18″ overall diameter, 235/55R20 turns 668 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 55% aspect ratio gives it a moderate sidewall suited to sporty street driving and responsive turn-in. 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 255/50R20 drops diameter by 0.46%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 245/55R20 adds 1.44% 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 30.18″ stock diameter (about ±2% in percentage terms) will keep ABS, TPMS, and odometer readings inside the vehicle's designed tolerance.

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