I have a twin engine jetter that I have built and installed in my van. It takes up alot of space. 16 gpm @ 4000 psi combined and 8 gpm @ 4000 psi with single engine. The large 250 gallon tank takes up the most room. I got this machine because I was used to the US Jetting trailer unit and wanted the unit in the van for winters. From past posts it seems like what I have is just over kill. I was thinking of taking out one engine and using a smaller tank and setting up my warthogs for that flow and psi. The largest lines I will be jetting will be 12" farm lagoon lines. The majority of the time will be 4", 6", and 8" lines with roots. Single engine or two give me your opinions.