Step 1) Preheat grill to medium-low heat (350 to 400°F).
Step 2) Combine all ingredients except pork in a bowl or resealable plastic bag; mix well to dissolve sugar and salt. Add pork and marinate for at least 15 minutes (or up to overnight).
Step 3) Remove pork from marinade, reserving marinade. Grill tenderloins for 40 to 45 minutes, turning once, until cooked through. Remove from grill and let rest on cutting board.
Step 4) While pork is grilling, pour reserved marinade into a small saucepan; bring to a boil. Simmer for 7 to 10 minutes, stirring constantly until thickened enough to coat spoon. Pour through a strainer into a small bowl and set aside.
Step 5) Slice pork across the grain into medallions. Transfer medallions to serving plate and drizzle with Balsamic Glaze.