Trim fat from steaks. Place steaks in a single layer in a shallow dish. For rub, in a small bowl combine chili powder, oil, oregano, salt, and cumin. Sprinkle spice mixture evenly over both sides of each steak; rub in with your fingers. Cover and marinate in the refrigerator for at least 1 hour or up to 2 hours.
Place steaks on the rack of an uncovered grill directly over medium coals. Grill until desired doneness, turning once halfway through grilling. Allow 11 to 15 minutes for medium-rare doneness (145 degree F) or 14 to 18 minutes for medium doneness (160 degree F). Cut each steak in half. Makes 4 servings.