Question: is 1.28 gallons per flush enough?
Answer: Maximum performance (MaP) testing conducted by independent agencies determines how much solid waste a toilet can handle. A rating of 350 to 600 grams for a 1.6-gallon flush is good, although some toilets can handle up to 1,000 grams (2.2 pounds!) using only 1.28 gpf. To find a toilet's MaP score, go to MaP Testing.