Mix marinade ingredients together in a freezer bag or airtight container. Add Tri Tip and seal bag or container, making sure the marinade surrounds and covers the Tri Tip.
Place in fridge and marinate for at least 3 hours, preferably 8 to 10 hours.
Remove meat from fridge to bring to room temperature, approximately 1 hour.
Turn grill on to high. Grill the Tri Tip on both sides over a direct flame to get a slight char, about 5 minutes per side.
Turn off the grill center flame and close lid almost completely to continue grilling over indirect heat, maintaining a grill temperature of about 450 degrees. Cook the meat until its internal temperature reaches 140 degrees for medium rare, approximately 20 more minutes.
Remove meat from grill, cover with foil, and let rest for 10 minutes before slicing thinly against the grain.
