Check the user manual. The default program is usually not the most energy and water efficient one but rather the mandatory one for certifying the machine.
Same thing for dishwashers, the “eco” program is often not the best especially if you have an “auto” one.
As it's the one for certifying the machine, it usually is the most energy and water efficient one. For washing machines the downside is that it takes 3 hours (or longer, if the machine was built before the EU capped it to 3h), for dishwashers the downside is that it stops being efficient once you realize that you have to run it a second time to actually get clean dishes.
For my new Bosch Benchmark dishwasher, "normal" actually uses 2.4 gallons and 1.25 kwh a load, is most efficient, and is quietest. There is no "eco" mode. "Auto" mode uses about twice the gallons no matter what's inside and slightly more kwh.
Maybe it’s a European thing. The eco program is the one mandated by law and the one they use for the energy rating.
But for machines that have a table showing power and water use, it’s never the most efficient one (in all the ones I checked). There is always a better program, it’s usually called “auto”.
Maybe it’s different in North America, idk what the rules are there.
I've heard this before (and I don't have any reason to doubt your research) but I'm struggling to figure out why it would be the case.
Regulation 1016/2010 (https://eur-lex.europa.eu/eli/reg/2010/1016/oj/eng) is the thing that establishes the various requirements for home dishwashers. It's pretty straightforward (most of the content establishing how efficiency is calculated). It basically just requires the default program to be "suitable to clean normally soiled tableware and that it is the most efficient programme in terms of its combined energy and water consumption for that type of tableware".
I could imagine some issues with how these numbers are calculated that reward "less efficient" devices or something like that, but it's pretty hard to figure out what that could be. Bit of a mystery!
Seems like the companies think we're too dumb in North America. My machines didn't come with any sort of tables. Someone else was saying their washing machine has actual temperature settings and RPM settings. None of the ones I've seen here tell us that, not even in the manual.
I try to explain this to people, but they are so convinced by the 'eco' branding/rethoric that even when you demonstrate they still disbelieve, or more acuratly do not want to believe.
Yes, check the power and water usage table in the manual: all the ones I’ve checked (in Europe), the eco program is not eco when compared to others (especially auto if it’s there)
Eco is just the standard program they have to ship and must use for the energy efficiency rating.
My understanding is that the standard program doesn’t allow for the optimizations that other programs do. It’s something like “must wash at 60C for 2h and perform a rinse cycle for 30 minutes” or something to that effect, so that everyone runs the same program and can compare ratings.
Whereas with other programs they can adjust the settings and times to make it wash better AND use less water/energy.
Because everyone would cheat and include a program that sprays cold water for a few seconds, using minimal energy but not actually getting your dishes clean.
Same thing for dishwashers, the “eco” program is often not the best especially if you have an “auto” one.