Why do economy wash settings take much longer?

I’ve been asked the following question many times -

How is it that the ‘Economy’ cycles take twice as long as the regular wash? How is that economical? I would have thought that would use more electricity.

Here’s the answer: Heating up the water in a washing machine or dishwasher is what really costs money. Just washing, with the heater turned off hardly uses any electricity. For example, a washing machine running with the heater on for 15 minutes would use considerably more electricity than a washing machine just washing the clothes with the heater off for hours.

The economy wash programs need to use less electricity to save money, so they use lower temperatures, and because that isn’t as efficient at washing as when using hotter water they have to compensate by physically washing for longer. So although the economy washes take longer, they use less electricity.