[Dr. Sivana]

My pet theory is that New Coke was always meant to be a temporary and not a permanent Coca-Cola brand product.

When that suggestion to Coke was made, the response was "We're not that smart, and we aren't that stupid."

In fact, Coke had already started switching over to HFCS years before new Coke, as had other companies. It has been suggested that New Coke would be cheaper to make because the classic formula contains a bit of "lime juice" under natural flavors, and that costs more.

[BradyLS]

Thank you for the correction. A misconception on my part.

[sloanrb]

The main reason New Coke tasted different:

It used the Diet Coke formula as its base. They tweaked the formula and added HCFS as the sweetener.