McDonald's Coke tastes different because McDonald's uses several special methods to enhance the flavor. They adjust the syrup-to-water ratio, making their Coke more concentrated to account for ice melting and diluting the drink. This means the drink has a higher syrup content than usual. Additionally, McDonald's filters and pre-chills their water and syrup before mixing, ensuring cold, fresh Coke with consistent quality. They also receive their syrup in stainless steel tanks (not plastic bags like many other places), which helps keep the syrup fresher. Furthermore, McDonald's uses wider straws that enhance the flavor experience by delivering more soda per sip. All these factors combined result in a Coke taste that is often perceived as superior or different compared to other sources.