I personally would not use a machine that small, it might slowly do the job but if you are going to start pushing into powerwashing I would make an investment in a bigger machine and keep that as a back up.
Some might say speed is not important but We are doing 3 jobs today if we were using that machine we would not finish until late into the evening, I would not have even booked 3 jobs today. That machine in summer would be so slow it would cost me money to use.