Many low cost consumer units utilize low pressure down stream soap injection and the fresh water is direct fed from a water source (garden hose). This requires the operator to change nozzles or adjust the wand to reduce the pressure to a few hundred pounds (PSI). This provides soap application similar to a soap bucket and offers very little cleaning action without manual agitation with a sponge or brush.

High pressure soap application draws cleaning products directly into the pump and discharges them at full pressure. This requires no nozzle/wand changes and is controlled with a valve at the pump. High pressure soap application provides maximum cleaning performance and control but usually requires a small on board suction tank in which the water supply (garden hose) is attached. This may increase the cost of the washer but provides far superior cleaning.