Laundry underclocking

Apparently, great strides have been made in energy- and water- efficiency for many household appliances - boilers, washing machines, dishwashers, etc. This is of course a Good Thing. The problem is that taking advantage of this new technology requires you to buy a completely new appliance, with all the environmental impact and cost associated with the construction of the new appliance and the disposal of the old one. I wonder if it's possible to upgrade older models in-place to be more efficient?