I have a Karcher 1740 psi washer. On vehicles, I only use it for cleaning wheel wells, etc., even though it has an adjustable nozzle. I just have an aversion to using it on the paint. I am an old fashioned 2 bucket method kind of guy when it comes to washing. Of course I do not detail professionally and I am sure others on this board will have a lot more opinions to share with you.