Depends on what counts as "one sitting", if you mean no serious breaks constantly going only stopping to burp and breathe a 2 liter. If you can count it if it's over the span of a couple hours but still one extended session 5 liters.
5 months
Largest amount of soda you’ve drank in one sitting
Two and a half liters. Couldn't do more than that. It was the fullest I have ever been. It seriously felt like I was going to burst. This was quite a while ago and my capasity is now bigger so could probably try to do more. Maybe at least three liters...
5 months
Largest amount of soda you’ve drank in one sitting