Use the live comparison above to see the exact diameter, circumference, revs/mile, and speedometer error between 285/75R17 and 315/70R17. Change either size to explore a different pairing, or open the full Tire Size calculator to start from scratch.
Tire Size Comparison
285/75R17 vs 315/70R17
Diameter, circumference, revs/mile, and speedometer error for 285/75R17 vs 315/70R17, with a to-scale visual.
Metric (285/75R16) or inch (35x12.50R17)
Past +10% diameter, budget for a regear. Use the Gear Ratio calculator to check.
Tire Size Results
First Tire
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stock diameter
Second Tire
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new diameter
Speedo Error
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speedometer error
| Measurement | First | Second |
|---|
285/75R17 vs 315/70R17: What Changes
Owners cross-shopping these two are usually deciding between a proven 33 (285/75R17) and a wider, marginally taller alternative (315/70R17) that fills the fenders more aggressively. The diameters are close, so the real decision is width and stance, and whether your wheel backspacing and fenders can accommodate the extra rubber.
Frequently Asked Questions
Is 315/70R17 taller than 285/75R17?
Only slightly. Both are in the 34-inch range; the 315/70R17 is a touch taller and noticeably wider. The results above give the precise numbers.
Do I need wider wheels for 315/70R17?
Not necessarily wider, but backspacing matters. The extra section width of a 315 often needs a wheel with the right offset to avoid rubbing the fender or upper control arm at full lock.