In a small bowl or using a mortar & pestle, mix the minced garlic, 2 tablespoons lime juice, 1 tablespoon liquid smoke, 2 teaspoons onion powder, 2 teaspoons sea salt, 1 teaspoon paprika and 1 teaspoon pepper to form a paste.
Add enough apple juice to make the paste easy to spread.
Spread paste evenly over the meat and allow to sit at least 1 hour, longer is better.
NOTE: If using a dry rub, apply 1 tablespoon per pound of meat by rubbing into the meat and allow to sit at least 40 minutes before grilling.
For Propane Grills:
When ready to grill, heat a gas grill on high until over 400 degrees (10-15 minutes).
Once hot (425°F or higher), clean grates with a wire brush.
Create two zones of heat by turning one of the burners off on one side while keeping the others on med-high.
For Charcoal Grills:
Light wood briquettes in a charcoal chimney starter and allow to burn until 90% of the coals are glowing and hot (15 minutes).
Dump hot coals into one side of the grill, leaving the other side open.
Place the grill grate and clean with a wire brush.
Grilling the Tri-Tip:
Start tri-tip fat side up and sear the meat directly over the hot side of the grill for 5-7 minutes. Turn and sear the other side for 5-7 minutes.
Move the meat to the cooler side, over indirect heat, and continue to cook for about 15 minutes (turn as needed) until the thickest part is medium rare (130-135ºF). TIP: To help the roast cook more evenly, position the thicker part toward the coals with the thinner ends pointing away once it is moved to finish cooking on the indirect heat side.
The thickness of the roast and desired doneness will dictate the remaining cooking time.
Once the roast reaches the desired temperature, remove from the grill and transfer to a cutting board, tent loosely with aluminum foil, and allow to rest for 10 minutes.
Carve by slicing against or across the grain -- this is especially important to ensure a tender texture when serving the finished roast.
Total time includes marinating or using a rub and resting time.
Some tri-tip roasts are sold untrimmed which means there can be a fairly thick layer of fat on one side. If that is the case, trim this layer to a little less than 1/4" thick.
If the tri-tip roast has been trimmed and little fat is present on the outside, drizzle with olive oil on each side during the cooking process to help keep the meat from drying out.
For a special finish, top the Tri-Tip roast or steaks with herbed compound butter once removed from the grill.