Preheat an outdoor grill to medium-high heat. Brush grill grate with oil.
Grill corn, turning occasionally, until fully cooked and lightly charred, 10 to 12 minutes.
While corn is cooking, mix sour cream and mayonnaise together in a small bowl until well combined. Place butter in a separate bowl and melt. In another small bowl combine chili powder and cayenne pepper. Set all three bowls aside.
Remove from the grill and immediately brush with melted butter, then spread each evenly with the sour cream mixture. Sprinkle with cheese and chili mixture. Garnish with cilantro and serve with lime wedges on the side.
*Nutritional information is an estimate. Please consult a doctor or nutritionist for the most accurate nutritional info.