Found this…..
The factory rear tire size for a 2014 Corvette (C7) is 285/30R20 on a 20”x10” wheel with a +79mm offset for the Z51 package, and 285/35R19 on a 19”x10” wheel with the standard setup. A 315 tire (such as 315/30R20 or 315/35R20) is significantly wider than stock and can fit only under certain conditions:
• Wheel Width: You need at least a 10.5” wide wheel, but an 11” or 11.5” wheel is preferable for optimal fitment and handling. Fitting a 315 tire on a 10” wheel is not recommended, as the tire will “balloon,” leading to poor handling and excessive wear.
• Offset: The correct wheel offset is crucial. Using the factory +79mm offset may push the wider tire too inward, risking rubbing on the inner fender or suspension components. Custom offsets (lower than +79mm) are commonly used to fit 315s properly.
• Clearance: Some owners report that a 315/35R20 can rub slightly on the inside, potentially contacting a small bolt or liner when the suspension is compressed, especially if the car is heavily loaded or the suspension is lowered. Minor modifications (like trimming or relocating a bolt) may be needed.
Summary:
• Yes, 315 tires can fit on a 2014 Corvette if you use at least an 11” wide wheel with a suitable offset, and you may need minor modifications to prevent rubbing.
• If on stock wheels (10” wide, +79mm offset), 315s are not recommended.
• Rubbing is possible on big bumps or with passengers/luggage in the car, especially if the suspension bottoms out.
