A wider tire on the front will increase oversteer, unless the front sway bar is stiffened (or the rear sway bar is decreased in stiffness) to compensate.
The right combo depends on the width of your rear tires, your sway bars, and the stiffness of your shocks&springs or coilovers.
The right combo depends on the width of your rear tires, your sway bars, and the stiffness of your shocks&springs or coilovers.