I used a Ryobi GCV190 Honda engine 3300 psi, 2.3 GPM. This surface washer seems solidly built. The caster wheel mounts are much more sturdy than I feared they'd be. It rolls easily on a flat surface. There was no water leakage from any outside connections over 3 hours of use. It is surprisingly quiet on a smooth surface. I only used one of the two supplied 24" extensions added to my wand. Using both would have been unnecessary for me, and too flexible, unless you ONLY push/pull. I'm very happy with this for first time use, & trust it will give years of service. We'll see how it holds up over time. (A few years ago I bought a 15" plastic one without wheels from Wally World for $23. It quickly fell apart, because of very poor design: its spinning nozzle turned counterclockwise, turning off the threaded nut that held it on!!)