Bring first 6 ingredients to a boil in large saucepan over medium-high heat. Reduce heat to low, and simmer 30 minutes. Reserve 1 cup mixture.
Grill pork, without grill lid, over medium-high heat (350° to 400°) 10 to 12 minutes on each side or until a meat thermometer inserted in thickest portion of tenderloin registers 155°, basting often with remaining vinegar mixture. Remove from grill, and let stand 10 minutes or until temperature registers 160°. Serve with reserved 1 cup vinegar mixture.
Note: For testing purposes only, we used Texas Pete Hot Sauce.