Whisk together the vinegar, oil, garlic, salt, pepper, garlic powder, onion powder, oregano, and smoked paprika in a small bowl. Pour the marinade into a large resealable bag or shallow dish.

Add the tri-tip and turn to coat. Seal and refrigerate for at least 30 minutes or up to 4 hours, flipping once.

Set up a grill for two-zone cooking with the hot side around 400°F (200°C). Remove the tri-tip from the marinade, sear over direct heat for about 4 minutes per side, then move to the indirect side. Close the lid and cook until an instant-read thermometer registers 130°F (54°C) for medium-rare, 10 to 15 minutes longer.

Rest the roast on a board, tented with foil, for 10 minutes. Slice against the grain and serve with any carving juices.