255/60R18
255/60R18 ships as an OEM size on the Acura MDX, Honda Pilot, Mazda CX-9. At 30.05″ diameter with a 6.02″ sidewall (60% of section width), this size turns 671 revolutions per mile.
About 255/60R18
Factory fitments for 255/60R18 include the Acura MDX, Honda Pilot, Mazda CX-9, Nissan Pathfinder — meaning replacement tires in this size see steady demand and broad brand availability. At 30.05″ overall diameter, 255/60R18 turns 671 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 18″ rim pairing is typical for full-size truck, premium SUV, and sport-sedan platforms, so compatible wheels are easy to source new or used. Going one step shorter to 235/65R18 drops diameter by 0.07%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 245/65R18 adds 1.64% 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 30.05″ 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 aliases255/60R18
- Diameter
- 30.05″ / 763.2mm
- Section Width
- 10.04″
- Sidewall
- 6.02″ / 153mm
- Circumference
- 94.4″
- Revs/Mile
- 671
235/60R18
- Diameter
- 29.1″ / 739.2mm
- Section Width
- 9.25″
- Sidewall
- 5.55″ / 141mm
- Circumference
- 91.43″
- Revs/Mile
- 693
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 58.11 mph (93.52 km/h). Your speedometer reads 3.14% high versus actual speed.