Light a grill. On a sheet pan, toss the corn with the oil, then season with salt and pepper
In a small bowl, stir together 2/3 cup of the cotija cheesewith the mayo, sour cream, cilantro, lime zest and Chile powder to combine.
Place the corn on the hottest part of the grill and cook, turning as needed, until cooked through and charred 8 to 10 minutes.