I have 15x8 Magnums on the 300 now. The Magnums fill the 'tubs' almost to the inside of the inner fenders, maybe about an 1" of cushion before they would touch the inner fenders. I put these road wheels on yesterday just to see how they would look....omg are they skinny! I don't know. There must be maybe 5" of clearance to the inside of the rear fenders compared to the Magnums. I'm going to clean them up, probably have chrome removed, paint argent silver, have the caps rechromed, and polish the trim rings. Think I would keep the white walls. Need to research max tire size for these 6" wide wheels. That's the plan for now lol.