Pour 2 tablespoons vegetable oil into a 5- to 6-quart pan over medium-high heat. Add turkey wing tips and neck and brown well, 4 to 7 minutes. Add 4 1/2 cups low-sodium chicken broth and bring to a boil; cover, reduce heat, and simmer about 1 hour. Remove wings and neck.
While roasted turkey rests, pour pan juices into a 1- to 2-quart glass measure. Skim off and reserve fat. Add turkey wing broth to make 4 cups; if you don't have enough, add water. Return 1/3 cup fat (if not enough, add butter) and 1 clove peeled and minced garlic to unwashed roasting pan; set over two medium-hot burners. Add 1/2 cup all-purpose flour and stir until bubbly and smooth. Stir in the 4 cups broth and 1 cup whipping cream; scrape pan sides and bottom to loosen browned bits. Whisk gravy until smooth and boiling, 4 to 7 minutes. Add salt to taste.
Note: In nutritional analysis, sodium is N/A.