So, I decided to look into what is better, washing your car by hand or washing it at a car wash. Well, as it turned out, the results were quite surprising.
As it turns out, washing your car at home (not a dry wash which is only good for small jobs) takes up 80 to 140 gallons of water. On the other hand, a commercial car wash uses 45 gallons of water for each wash. In addition, federal laws in the U.S. and Canada require commercial car wash facilities to drain their waste water into sewer systems, where they are treated and discharged back into the environment as clean water. Commercial car washes also use control systems to minimize water usage because too much water usage will cost them money. On top of that, there are many car washes that recycle and reuse their rinse water.
When people wash their car at home, the water and soap goes down the driveway and into the storm sewer, which then makes its way into the environment without being treated.
So, on the rare occasion we wash our car, which we do not have to do often because we do not drive much, we will be taking our car to a car wash.