Lay two ears of corn each on two separate pieces of aluminum foil large enough to wrap the ears completely. Place 1 teaspoon butter, 1 teaspoon garlic powder, and 2 teaspoons minced garlic on top of each bundle of corn. Season with salt and pepper. Tightly wrap the corn in the foil.
Cook on preheated grill for 10 minutes; turn. Continue to cook another 10 to 14 minutes.