I found this great survey on toilets. Veritec, a testing company, tested 700 toilets for flush power, water savings, bowl size, flapper size etc. Now this might not excite most people but when you are looking for the most water efficient toilet that also actually flushes everything down this study is amazing.
13th-edition-full-toilet-veritec-report
It shows that clearly not all toilets are equal.
What makes their study great is that they tested the toilets using realistic situations. No they didn’t crap in all 700 hundred toilets. But they did use a soy based paste shaped to look damn convincing.
This is noteworthy in the toilet industry since all tests before them were done with idiotic test materials like ping pong balls and confetti. Obviously this isn’t realistic, unless of course you just came from a really weird ping pong match where you celebrated with confetti, most people don’t crap that sort of stuff.
Anyway, it is better to use the survey backwards, meaning instead of pouring over the 700 toilets to try and find the best one, go to the store and find one you like then look it up on the list. If it matches up to par then great. If not then move on.
You want a WaterSence Certified Toilet. You want it to use 1.28 gallons of water or less. Dual flush isn’t absolutely crucial in my eyes. Not always but most of the time if it’s yellow you can let it mellow.
But you also want it to be able to pass a certain amount of material, called the MaP Flush Performance MFP. A Brittish study showed that most males crap an average maximum of 250 grams, with a 95th percentile crapping just over 300 grams. Women crapped a little less.
I’d say that on average Americans are a little more full of crap than British. But green minded people I would say tend to not be your average American Glutton so this study is applicable to US green toilets in my mind.
The Veritc study suggests toilets have at least a flush power of 250 grams. The US EPA has a minimum flush power restriction of 350g. Truth be told most toilets flush a lot more than that since they need to prepare for the worst. In the 700 toilet study the flush power ranged from the EPA minimum of 350g to a shit kicking 1000g. Their calculations stopped at 1000g so there are actually toilets that go above 1000g/flush.