If you decided to buy a new toilet, you might have noticed that terms such as “1.28 GPF” and “1.6 GPF” are mentioned quite often. These are related to how much water a toilet needs per flush – GPF stands for “gallons per flush”.
Although the difference is less than half a gallon, choosing one over the other can have a big impact, so it’s important to mention the upsides and downsides of both rates.
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Low Water Consumption Toilets
Both 1.28 and 1.6 GPF toilets are low-water-consumption units. These units were introduced back in 1994 after American President George Bush signed the Environmental Protection Agency, or EPA, into law, which demands that toilets not use over 1.6 gallons of water per flush. This new restriction motivated many toilet manufacturers to rethink their current designs, as most toilets used over 1.6 gallons per flush at the time.
Since some toilets required more than one flush to remove all waste, manufacturers had to find a solution to make low water consumption more effective. Not only did they improve toilet efficiency, but they managed to find a way to build an effective toilet that uses less than 1.28 gallons per flush by implementing bigger flush valves and redesigning the bowls. Through these advancements, manufacturers were able to meet EPA guidelines with an efficient flushing system.
Difference Between 1.28 GPF and 1.6 GPF Toilets
The primary difference between these two types of units is related to their flushing power. However, the flush volume doesn’t necessarily mean that 1.6 GPF units are more powerful. Let’s take a look at the Toto Ultramax II (1.28 GPF) and the American Standard Champion 4 (1.6 GPF). These toilets come at a very similar price and are both one-piece models. However, the Toto Ultramax II is more powerful, although it consumes only 1.28 gallons per flush. The main reason is that the Ultramax II features Toto’s powerful Tornado Flush technology which applies a lot of force even while using a small amount of water.
Another detail that sets these two types of toilets apart is their water efficiency. The difference between 1.28 and 1.6 gallons doesn’t seem to be significant, so you might be wondering whether 1.28 units really save water. However, even part of a gallon adds up over time. Since you would save 0.32 gallons of water with every flush, you’ll actually use 20% less water. Annually, you can save over $100 just by using a 1.28 GPF toilet over its 1.6 GPF counterpart. Of course, you will save even more by comparison if you live in a family with four or more people.
Finally, 1.28 GPF units are more eco-friendly. For example, an average family can save over 2300 gallons of water annually by installing a 1.28 GPF model. Especially if you select a powerful model like the Ultramax II, you can save money and water without compromising performance with a 1.28 GPF toilet.
High-Efficiency Toilets & Low Water Consumption
Thanks to the new EPA restrictions, manufacturers had to find a way to maximize impact with only 1.28 gallons of water. One of the first things they added to their toilets was a bigger flush valve. With a bigger flush valve, water creates greater force, which directly improves flush efficiency. Also, manufacturers had to redesign their toilet bowls. While older units usually had rim holes for water to pass, newer models feature technologies that help maximize the flush itself. For example, instead of rim holes, these models have two nozzles at each side of the bowl to create a powerful siphon action.
Some manufacturers also noticed that the toilet flapper restricts water flow. To remedy this, instead of the flapper flush valve, they installed canister flush valves. Their main advantage is that they allow the water to flow to the tank from an angle of 36-degrees. Some toilets even have pressure vessels, which compress the air and force the water at a higher speed.
Pros and Cons
By comparison, 1.6 GPF toilets leave no doubt in their flush efficiency. Due to their effective flush, you will also spend less time maintaining the toilet. On the other hand, they use more water which leads to increased costs in the long term, and they can be quite loud.
Read our guides of different 1.28 GPF and 1.6 GPF toilets from these popular manufactures, TOTO reviews and Kohler reviews, and American Standard reviews
Frequently Asked Questions
Are 1.6 GPF Toilets Allowed in California?
No, they are not. Due to the California Energy Commission, all units that are sold in California must use 1.28 gallons per flush or less.
What Toilet Brands Should I Look For?
Buying a toilet from a popular brand is a great way have confidence in the toilet you select. We strongly advise you to check out the units manufactured by Toto, Kohler, American Standard, and Saniflo. You can search our website for recommendations of top models to try as well.
What Is the Highest GPF Toilet?
Most toilets today use up to 1.6 gallons per flush. However, some older models can use as much as 4 gallons or more, which leads to lots of money wasted at the end of the year, especially if you live in a large family.
Does a high-efficiency toilet save me money?
Yes – as discussed, by consuming 20% less water with each flush, you’ll save on your water bills every year. Further, depending on your location, you could be eligible for additional rebates through the EPA’s WaterSense program.
Final Verdict
As you can see, 1.28 GPF units have numerous advantages. If you are looking for a quiet, eco-friendly toilet that uses a minimal amount of water but performs well, buying a 1.28 GPF model is an excellent choice. However, if you’re unable to find a 1.28 GPF model from a top brand, it may be worth considering a 1.6 GPF model if flush efficiency is not your top concern.