I've got 2. A 5hp 2000psi Honda gc engine. Use it on most things. Then there's the northern tool 4000psi 13hp honda beast. The 4000psi only gets used if I have a lot of surface cleaning. Its fast and strong and will wear you out. I do reccomend spending a little extra and you get a belt drive unit. They are gear reduced pumps that spin at 1800rpms and last a long time. Both my washers have cat pumps and I've had them many years