Why was New Coke introduced in 1985?

The Coca-Cola Company introduced New Coke in 1985 primarily to address declining market share and respond to the competitive pressure from Pepsi.12

For years, Pepsi had successfully utilized the "Pepsi Challenge" advertising campaign, which featured blind taste tests where participants frequently preferred the sweeter taste of Pepsi over the original Coke formula. Concerned by these results, as well as falling supermarket sales and potential risks to lucrative soda fountain contracts with major fast-food chains like McDonald’s and Burger King, Coca-Cola executives decided to reformulate their flagship product.12

Following extensive internal testing that indicated a preference for a sweeter, slightly flatter recipe, the company launched New Coke in April 1985. However, the move was met with significant public backlash, leading the company to reintroduce the original formula as "Coca-Cola Classic" just 79 days later.12