How long can you keep Mountain Dew until it goes bad?

Unopened cans or bottles of soda like Mountain Dew can stay fresh at room temperature for about 9 to 12 months from the date that they were packaged or bottled, according to the United States Food and Drug Administration (FDA).

Once opened, soda will usually last for about 3 to 4 days in the refrigerator before it starts to lose flavor and become flat.

For the best taste, consume Mountain Dew within 6 months of purchase.