“Oil the food, not the grate” is a barbecue motto that I live by. If you put oil on the grate of a grill hotter than the oil’s smoke point (above 400°F), as so many recipes instruct you to do, the oil burns instantly. The resulting carbon layer can make sticking worse and doesn’t taste good, either. Because food that’s oiled is cooler than the grill grate, it cools down the grate, and the oil doesn’t burn on contact. Also, oiling the food isn’t wasteful because you use just what’s needed to cover the food.