Tire RulerWhat changes when you switch to 315/70R17
- Height: +0.36″ (+1.1%), so ground clearance at the axle goes up 0.18″.
- Width: +1.90″ (48 mm). Check inner clearance to the suspension and frame, and the fender liner at full lock.
- Sidewall: +0.18″. A taller sidewall rides a bit softer and protects the wheel off-road.
- Revolutions per mile: 593 → 587. Your gears act about 1.1% taller; at 65 mph in a 0.69 top gear with 3.73s, that’s 1,654 → 1,636 RPM.
Sizes are theoretical, from the sidewall code. The same size can differ by a few tenths of an inch between brands and tread patterns; check the maker’s spec sheet for the exact model.
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Frequently asked questions
How much bigger is 315/70R17 than 34x10.50R17?
315/70R17 is 0.36 inches (1.1%) taller and 1.90 inches wider: 34.4" × 12.4" versus 34.0" × 10.5".
Will 315/70R17 change my speedometer?
Yes, by 1.1%. Going from 34x10.50R17 to 315/70R17, an indicated 60 mph is about 60.6 mph.
Can I replace 34x10.50R17 with 315/70R17?
Often, yes: the height difference is within the ±3% most tire shops accept. Both fit a 17" wheel; confirm the rim width, load index and clearance for your vehicle.
Do I need to regear going from 34x10.50R17 to 315/70R17?
Usually not for a 1.1% change. With 3.73 gears, the 315/70R17 acts like 3.69.