Combine all dry rub ingredients in a small container and set aside.
Trim the silver skin and fat layer from the trip tip. Place on a sheet of plastic wrap.
Generously coat the tri-tip with about 4 tablespoons of dry rub, 2 tablespoons on each side. Store extra seasonings in an airtight container for later use.
Tightly wrap the tri-tip and refrigerate until ready to use. Allow the rub to settle into the meat for at least 3 hours or up to 3 days.
When ready to grill, remove the seasoned tri-tip from the refrigerator and allow it to come to room temperature, about 1 hour.
Clean grill and lightly oil the grates using a paper towel dipped in vegetable oil.
Heat the grill to medium-high if using a gas grill. Once hot, place the meat on the grill and sear one side for 10 minutes with the lid open.
Turn tri-tip over and sear for another 10 minutes. Turn the heat down to medium and close the lid.
Allow the meat to cook for about 15-25 minutes, checking the temperature until the thickest part reaches 120-125°F (medium-rare) or 130-135°F (medium).
The meat will continue to cook after being removed from the heat, so stop cooking a few degrees lower than the desired doneness.
Remove the tri-tip from the grill and allow it to rest wrapped loosely in foil for at least 15 minutes before slicing. The foil will catch any juices from the meat, which can be added back to the meat after slicing for more flavor.