
Heat the grill to 400°F.
Grill the ears of corn until slightly charred and tender, about 12 minutes, turning occasionally.
While the corn is cooking, stir together the mayonnaise, sour cream, lime juice, and zest in a small bowl.
Using a brush, slather the mayonnaise mixture all over the grilled corn. Sprinkle with cheese and chili powder and garnish with chopped cilantro. Serve immediately with lime wedges on the side.