This table list my current testing results of the efficiency of Soda Makers. This essentially measure how good a machine is at turning liquid co2 from a cylinder, into dissolved co2 in water or another liquid.
| Model | Efficiency % (higher better) | Cylinder to Water Ratio (lower better) | Amazon Link |
| SodaStream Terra | 62% | 1.6x | https://amzn.to/4e6PktO |
| Aaarke Carbonator III | 45% | 2.2x | https://amzn.to/3X33wxF |
| DrinkMate OmniFizz | 43% | 2.3x | https://amzn.to/4hN711Z |
| Philips GoZero | 29% | 3.4x | https://amzn.to/3J22Kwv |
| SimpliSoda Blu | 23% | 4.4x | https://amzn.to/48rdleG |
No machine is perfect, so 1 gram of co2 in the cylinder never turns into 1 gram of extra mass in the bottle. But some machines are much more efficient than others.