Horizontal-axis washers (front-loaders) use 1/3 - 2/3 less water than vertical-axis machines (top-loaders), saving valuable water and energy resources. However, less water also means regular laundry detergents do not dissolve as easily and can leave soap residue on your clothes.
The tumbling action of an horizontal-axis machine is gentler on fabrics but adds more air to the water as your clothes are plunged into and lifted out of the water. This creates more suds than a conventional top-loading washer would, and excess suds can overflow and actually damage a front-loading machine.
To prevent excessive sudsing when using regular detergents in an horizontal-axis washer, it is often necessary to use substantially less detergent. However, using less detergent can result in poor cleaning. As a result, it is best to use a specially formulated low sudsing laundry detergent with a front load washer. This is where high efficiency laundry detergent comes into play.