When adding sour cream to a cake recipe, do you substitute it for the water?

There's a recipe that I use all the time called WASC, which adds sour cream to a box mix. Here's the recipe:





1 cake mix


1 cup flour


1 cup sugar


1 1/3 cup water


1 cup sour cream


1 tsp vanilla


1 tsp other flavoring (or more vanilla)


4 egg whites


1 tbsp oilWhen adding sour cream to a cake recipe, do you substitute it for the water?
Most times when substituting sour cream or yogurt into a cake mix, you replace the oil.