Can someone fill me in on OEM wheel/tire options? Is there a method to the madness?

Most manufacturers offer their base trim with something like a 17" wheel and an average all-season tire. As you increase the trim, it's common for them to offer a larger diameter wheel with a thinner sidewalled tire (to keep the absolute diameter of the combination the same at all trim levels).Naturally, this leads the consumer to believe that having a larger wheel and thin sidewalled tires is "better." Is it? Wouldn't the wheels be heavier, leading to worse performance? Do more powerful cars benefit from larger diameter wheels and low profile tires? What's the deal here?I may upgrade my wheels to an OEM 18" (with recommended tires) if there's a benefit but I wanted to be sure. Thanks everyone! via /r/cars http://ift.tt/2uynb8Y