The short term preliminary results are in. And so far... its good! On Wednesday the 12th I began an experiment to make a 2-liter bottle of soda last for as long as a 6 pack of soda with minimal extra expense and supplies. Here's how...
I bought a 2-liter bottle of Pepsi and one 6 pack of 10 oz. Canada Dry Tonic Water. The Canada Dry itself was not needed (I poured it all out). What I did need however, were the 6 hard glass 10 oz. bottles it come in. I filled each bottle to the top (to eliminate any extra space), screwed on the lids and stored in the fridge. Each day I opened up and drank one bottle to see it was still carbonated. Tonight I drank the last bottle and to my satisfaction was still carbonated.
If you want to try this at home, I recommend using the glass bottles like mine as opposed to plastic bottles like water bottles. Glass is much stronger and will hold a stronger pressure thus keeping more of the carbon dioxide in the soda. Also, they just last longer.
This was just a short term test. After tonight I will begin a longer two week test to see if the bottled soda can last about the longest that a normal 6 pack would in a fridge. I'm hoping this next test will yield similar results and will also be accompanied by a thorough of examination of the various ounces to dollars ratios to determine how much money is saved on each purchase as well over the course of a year.