255/50R17
255/50R17 is uncommon as OEM fitment but appears as an aftermarket upsize option. At 27.04″ diameter with a 5.02″ sidewall (50% of section width), this size turns 746 revolutions per mile.
About 255/50R17
255/50R17 is less common as a factory fitment but is available as an aftermarket size, so SKU selection is narrower than mainstream OEM sizes. At 27.04″ overall diameter, 255/50R17 turns 746 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 50% aspect ratio gives it a moderate sidewall suited to sporty street driving and responsive turn-in. The 17″ rim pairing is typical for light-truck, crossover, and mid-size SUV applications, so compatible wheels are easy to source new or used. Going one step shorter to 245/50R17 drops diameter by 1.46%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 235/55R17 adds 0.51% 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 27.04″ 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 aliases255/50R17
- Diameter
- 27.04″ / 686.8mm
- Section Width
- 10.04″
- Sidewall
- 5.02″ / 127.5mm
- Circumference
- 84.95″
- Revs/Mile
- 746
235/50R17
- Diameter
- 26.25″ / 666.8mm
- Section Width
- 9.25″
- Sidewall
- 4.63″ / 117.5mm
- Circumference
- 82.47″
- Revs/Mile
- 768
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 58.25 mph (93.75 km/h). Your speedometer reads 2.91% high versus actual speed.