When 1.6 makes sense
- You are in a state that permits it and the model you want is only made at 1.6.
- Your home has old, shallow-slope drain lines and a plumber has specifically recommended more water per flush.
- You are matching an existing toilet in a two-toilet bathroom.
Outside those cases there is little reason to choose it over 1.28.
Where 1.6 is not permitted
Several states have adopted 1.28 gallons as the legal maximum for new toilet installations, including California, Texas, Colorado and Georgia, with others following.
Rules change, so confirm your local requirements before ordering. If you are in one of those states, our 1.28 and 1.0 gallon models are the ones to look at.
Does 1.6 flush better?
Not on a modern TOTO. The same bowl and the same flushing system are used across flush volumes within a series. More water does not mean a better flush on current designs.