Combine first 3 ingredients in a shallow dish or large heavy-duty zip-top plastic bag; add tenderloins. Cover or seal, and chill 2 hours, turning occasionally.
Remove tenderloins from marinade, discarding marinade.
Grill, covered with grill lid, over high heat (400° to 500°) 6 to 7 1/2 minutes on each side or until a meat thermometer inserted into thickest portion registers 160°. Serve with Onion-Balsamic Sauce.