Toilets: what you need to know about flushing
If you haven't shopped for a new toilet in a while, then you might be in for a surprise about how fast the discussion can become complicated. You might even start tossing around terms like fluid dynamics, siphonic action, and dual-action flush technology. The good news is that toilets, regardless of whether they are the $200 value model or the top-of-the-line $1,500 model, all generally work the same way: they use water and gravity to push waste out of the home. The key differences really are aesthetic.
Toilets now come with a federally-mandated low flush rating. The high end uses 1.6 gallons, although you will come across models that are more conservative and use just 1.28 gallons a flush. When it was first introduced in the late 1990s, low-flush technology had a bad reputation. Now though, many of these kinks have been worked out and low flush toilets work well.