While I understand the need for some Energy Star guidelines to improve on old water guzzling, slow-spinning water and energy hog top load clothes washers, I am puzzled by the imposing of such standards on dishwashers. The automatic dishwasher was an efficient appliance before Energy Star. It had already been proved to be vastly more water and energy frugal than hand washing. (more sanitary too)

But, one can partially blame us whiny Boomers and our whinier Gen-X offspring for the 3 hour pee on the dishes water stream.  After all, because kitchens in many new homes are now part of what is known as the Great Room, we don’t want to hear machines when we are trying to watch TV and listen to our premium surround-sound 7.1 systems at deafening levels. (Whenever I’ve had to do the dishes by hand, I made much more noise complaining than any dishwasher ever did by operating) An easy way for manufacturers to make their machines quieter was to reduce the force of the water.  And the bonus was that this enabled machines to wash with much less hot water and much smaller motors.  

Of course it does make economic sense that manufacturers who were forced to re-design an appliance would also take the opportunity to make them less expensive to produce.   Electronic control panels have replaced mechanical timers to a great extent because the actual cost of the hardware is only a few dollars and is upgradeable with software. Like one AW member mentioned one wonders about the logic of putting electronic parts in an environment of heat, water, and steam.  

Tough question, though I think manufacturers might've "encouraged" EnergyStar because there are still people who think they can wash dishes with less water (and better than) any modern or vintage dishwasher. The more the usage is reduced: The more of these "greenies" they are likely to attract. More $ for the company and government too. Its a Win for them and a lose for us. 

Remember dishwashers were probably more frugal in the beginning: Mike's GE Electric Sinks I think would rank much better in usage than the machines coming through the 60s, 70s and 80s (Who used up to 18 gallons to wash dishes), before dropping back again through the 90's and into the 2000's. 

Depending on who you are, your hand-washing may/may not use as much water (Although proper hand-washing should be using much more water than a dishwasher: Rinse - Wash - Rinse and ensure plenty of water changes in your sink to ensure CLEAN dishes, not scummy, washed in black water dishes).

We must also observe machines from elsewhere in the world, like Europe where dishwashers (once they really penetrated the market) were already using half the water of their American counterparts. Obviously, the Americans used more water since it was cheaper and because their dishwashers had no filter, a self-cleaning filter combined with food disposals to make the dishwasher essentially maintenance free, whereas most EU machines had manual-clean filters, no disposal and were probably expected the be quiet.

I know of Asko machines from the early 1990's that used about 30L of water for two washes and three rinses and had a self-clean filter too, so obviously low water was doable, but some manufacturers cheaped out on their consumers and persisted with 20 year old pump/distribution systems (GE's dreaded "Tower-Wash" machines) - so money stopped development until the Government realised there was much to be improved upon. Maybe this explains the draconian rules/regulations imposed lately then...

= Fatty slime on your dishes

Hot water is required (at one point or another) in the dishwashing cycle to "melt" the grease and wash it away. I've found loads of really greasy items can often leave greasy residue inside the dishwasher, if you don't use the higher temperature washes for such items. A 122º wash and 140º Final Rinse don't quite cut it for those items.... You need a good 140º+ Wash and Final Rinse to get rid of that horrible stuff (Also means intermediate rinses are rather hot too, which certainly helps).