Here’s a toilet puzzle for you: Why don’t toilets in Brazil flush as efficiently as those in the United States and Canada? In Brazil it’s pretty standard to have a waste paper basket beside the toilet for throwing away toilet paper. Hotels and restaurants will have signs asking you to not flush toilet paper. In the USA and Canada nobody worries about flushing toilet paper.

The answer to this question is not obvious. Even luxurious toilets in expensive hotels do not flush as nicely as in Canada/US. It’s not a cultural or environmental thing to not flush toilet paper —- toilets really do get clogged very easily and getting rid of the toilet paper might take multiple flushes. I’ve seen Brazilian toilets that pass a lot of water per flush but still don’t work well.

My current theories are that either Brazil uses narrower diameter drain pipes or that they have a more elongated P-trap than in the US and Canada. Someday I hope to run into a master plumber who’s worked in both Brazil and North America to tell me what the difference is.

EDIT: The Quora link below says that the same problem happens in Mexico because the Y-fitting under the toilet doesn’t have graceful curves compared to US fittings and/or the drain is not sufficiently vented, so the toilet water flows slower. Both of these also sound like plausible theories.