Diet Coke
Diet Coke does not use a modified form of the Coca-Cola recipe, but instead an entirely different formula. The controversial New Coke, introduced in 1985, used a version of the Diet Coke recipe that contained high fructose corn syrup and had a slightly different balance of ingredients. In 2004, Coca-Cola introduced Coca-Cola C2, which it claims tastes much closer to Coca-Cola but contains half the carbohydrates. In 2005, the company introduced Coca-Cola Zero (replaced by "Coca-Cola Zero Sugar" in 2017), a sugar-free variation of regular Coca-Cola.
Diet Pepsi
Additional variations of Diet Pepsi have been introduced over the years, wherein other flavors (such as wild cherry, vanilla, lemon, and lime) have been added to the cola. A caffeine-free version of Diet Pepsi is also produced. The availability and brand identification of Diet Pepsi flavor variants varies by country. In addition to Diet Pepsi, PepsiCo also produces the low-calorie cola Pepsi Max.