285/60R20
285/60R20 is uncommon as OEM fitment but appears as an aftermarket upsize option. At 33.46″ diameter with a 6.73″ sidewall (60% of section width), this size turns 603 revolutions per mile.
About 285/60R20
285/60R20 is less common as a factory fitment but is available as an aftermarket size, so SKU selection is narrower than mainstream OEM sizes. At 33.46″ overall diameter, 285/60R20 turns 603 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 60% aspect ratio gives it a balanced sidewall — enough compliance for daily comfort without vague steering. 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 275/60R20 drops diameter by 1.41%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 265/65R20 adds 0.29% 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 33.46″ stock diameter (about ±2% in percentage terms) will keep ABS, TPMS, and odometer readings inside the vehicle's designed tolerance.
Compare with another size
275/65R18 or "33" for inch aliases285/60R20
- Diameter
- 33.46″ / 850mm
- Section Width
- 11.22″
- Sidewall
- 6.73″ / 171mm
- Circumference
- 105.13″
- Revs/Mile
- 603
265/60R20
- Diameter
- 32.52″ / 826mm
- Section Width
- 10.43″
- Sidewall
- 6.26″ / 159mm
- Circumference
- 102.16″
- Revs/Mile
- 620
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 58.31 mph (93.83 km/h). Your speedometer reads 2.82% high versus actual speed.