I have a Laser 4000 that injects soap mixed with air to the bay (it pulls straight from the presoak barrel and mixes air and water as it goes to the bay). It gives 1250 passes per 50 gallons. My other washes pump soap from a hydrominder mix bin, and air is injected as it goes to the bay. The best I can do by playing with the soap pump pressure (max 60 psi, Gould pump) and the air mix is 700 passes per 50 gallons of presoak. All systems are using the same presoak at 11.8 PH, and the passes are longer on the Laser so you would think it would use more.... Soap coverage appears the same at all washes, and all washes use approx. the same tips/gallons on the L-Bar. What is the difference? Why is the Laser with the injection system giving double the passes??