Mix first 7 ingredients in medium bowl. Using fork, mash in garlic. Using 3 tablespoons spice mixture for each steak, rub spices onto both sides of steaks. Whisk oil into remaining spice mixture; set oil rub aside. Place steaks into shallow dish. Cover; chill steaks and oil rub at least 4 hours and up to 24 hours.
Prepare BBQ (medium-high heat). Brush steaks with some of the oil rub. Grill steaks to desired doneness, brushing occasionally with oil rub. Use a meat thermometer to gauge when done.