Heat the grill to medium-high. Season the wings with salt and pepper.
Using grill tongs, dip a wad of paper towels in oil, then carefully rub the grill grate until glossy and coated. Grill the wings, covered, flipping occasionally, until they are golden brown, crispy and completely cooked through, about 20 minutes. Keep a close eye on the grill: if there are flare-ups or the wings begin to burn, move the wings to a cooler part of the grill or reduce the heat. You don't want grill marks on the wings; just a nice and even golden-brown color.
While the wings are cooking, make the sauce. Combine the butter and garlic in a microwave-safe bowl. Cook for about one minute in the microwave until the butter is melted. Stir in the hot sauce, salt, onion powder, chili powder and sugar. Set aside.
