In the pre-1970 period toilets were 6-12 gallons per flush. Then 5 gallons became standard, until 1992 when "low flush" toilets were the only kinds allowed to be manufactured in the United States. I have read plumbers making the rather unbelievable claim that modern 1.6 gallon toilets flush better than 6 gallon toilets. Is this just a plumber trying to justify his business or some kind of reality?
All I know is that I have a house built in 1999 and the toilets flush like crap to use a pun.