Begin by making the marinade by whisking the apple cider vinegar, dijon mustard, brown sugar, olive oil, garlic powder, kosher salt, onion powder, and black pepper together.
Once combined, pour the marinade into a large ziplock bag.
Next, take the pork tenderloin and trim off any excess skin or fat before adding it to the bag.
Once the meat is in the bag, zip it up and squish it around until the pork is fully coated in the marinade. Put this in the fridge for at least an hour or overnight.
Before you take it out of the bag to grill, squish it around one more time.
Once you’re ready to grill, brush the grill grates with oi to prevent the pork from sticking.