In a large bowl, stir together flour, sugar, baking powder, and salt. In a medium bowl, whisk together oil, egg yolks, lemon zest and juice, and ¼ cup water. Fold oil mixture into flour mixture.
In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites at high speed until stiff peaks form, about 2 minutes. Fold one-third of egg whites into batter. Gently fold in remaining egg whites. (Do not overmix.) Gently transfer batter to an ungreased 10-inch tube pan.
Bake until top springs back when lightly touched near center, about 1 hour. Immediately invert pan; let cool completely in pan, about 1½ hours.
Run a knife around edges and center of pan. Invert cake onto a wire rack. Pour Lemon Glaze over cooled cake. Garnish with lemon slices and peel, if desired.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/lemon-chiffon-cake-recipe/