In a small bowl, combine chili powder, cumin, oregano, 1 1/2 teaspoons salt, and 1/2 teaspoon pepper. Sprinkle mixture over steak; drizzle with oil. Let stand, turning to coat evenly with oil halfway through, about 10 minutes.
Heat grill to high; lightly oil grates. Place steak on grill (fold thin end over so steak is an even thickness); cover. Cook, turning once, until meat is desired doneness, 4 to 6 minutes for medium-rare.