Making Fully Mobile Pressure Washer

I decided to build a completely mobile washer that would be powered by an internal combustion engine and would have tanks, so I would not have to connect the water supply every time.
The washer turned out to be a very mobile machine, I washed two heavily soiled cars on one tank, including a large one, and about 1/4 of the water tank remained. The pressure washer is powerful and can be regulated by the speed of the internal combustion engine
I used biodegradable cleaners for washing the car, it does not harm the environment and plants