I passed a car wash whose height bar said 90” for their new
razor. No idea if the bar represents the old machine or if it has been updated for their
razor. I will ask when I see the owner in the next week. Our bar says 7’ however we have washed cars up to 7’4” when I was watching. Makes me nervous when I see the arm so close however I was curious. No plans to change the bar as we have people who push the limit so the margin for error is a good thing.
I have never seen any data on the impact change for the arm distance to the car. Would be interesting for a manufacturer to publish such a test. Maybe Petit will as their arms are a fixed distance from the car however they appear to use a tighter (5 deg) osculating nozzle and claim to have amazing results with that approach.