2. Rub the tri-tip roast with olive oil, garlic powder, onion powder, salt, and black pepper.
3. Place the tri-tip roast on the grill and cook for about 15 minutes on each side, or until the internal temperature reaches 130°F (54°C) for medium-rare.
4. Remove the roast from the grill and let it rest for 10 minutes before slicing.