Do Americans really need to wash dirty laundry for as long and with as much detergent as we do?

Just thinking about this in terms of both economics and the effect on the environment. The vast percentage of the clothes I wash for my family isn't really that dirty, or even very smelly. I've recently started cutting my detergent back by 50%, and wash for the shortest time setting on my washer. In fact, sometimes I just use the rinse cycle alone, putting in just a small amount of detergent. I can't tell any difference between the way my clothes look and smell now than they did before, except they wear longer! Do you think Americans should start taking a closer look at conserving in this way?