Car Washes: Home vs. Commercial Service

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Washing Vehicles by Hand

Taking a few simple steps when washing your boat or vehicle (including automobiles, trucks, motorcycles, and trailers) can help to conserve water and protect the quality of nearby water bodies.

  • Automatic Shutoff Nozzle - A standard garden hose uses about 10 gallons per minute. This means you use 100 gallons of water with only a 10-minute car wash. When you use an automatic shutoff nozzle on your hose, water does not flow continuously while you wash your vehicle, saving as much as 70 gallons per wash.
  • Power Washer - Using a power washer can conserve even more water; power washers use, on average, about two to five gallons per minute, with a potential savings of up to 80 gallons over using a standard hose without an automatic shutoff nozzle.
  • Use a Bucket of Soapy Water - Soap and water usually work well. If you need a special cleaning product for vehicles, read the label carefully and be sure to use a non-toxic, biodegradable detergent. Do not use a product that says "poison," "harmful," or "danger." Be sure to turn the running water off while you are washing a vehicle.
  • Wash Vehicles on Grass - Wash your vehicle over an unpaved area, such as an area covered with grass or gravel. This will allow the soapy water to soak into the ground, be filtered and eventually recharge the groundwater. If you have your own well, you should wash your vehicle at least 100 feet from the well head. If you wash the vehicle on a paved surface, the runoff flows into a storm drain and the water and contaminants are discharged to the nearest lake or stream.

Commercial Car Washes 

If you cannot wash your vehicle in an area that drains to the lawn or a gravel area, take it to a commercial spray booth or car wash. A properly designed car wash is connected to a sanitary sewer that carries the dirty water to a wastewater treatment plant.

There are three types of commercial car washes: self-serve car washes, in-bay automatic car washes and conveyor car washes. The following table provides water use information by car wash type. The data represents the total water used and does not take into account whether or not a car wash recycles its water.

Average Water Consumption by Car Wash Type 

Car Washing TypeInternational Car
Wash Association1
Mid-Atlantic Car
Wash Association
Commercial Conveyor66 to 85 gallons per vehicle60 gallons per vehicle30 to 50 gallons per vehicle
Commercial In-Bay50 to 60 gallons per vehicle35 gallons per vehicle65 to 100 gallons per vehicle
Commercial Self Serve15 gallons per vehicle15 gallons per vehiclen/a
Home wash - With automatic shut-off nozzlen/an/a30 gallons per vehicle
Home wash - Without automatic shutoff nozzle
  • Assumes a 15-minute car wash with flow of 10 gallons per minute
n/an/a100 gallons per vehicle

1 Brown, Chris. 2002. "Water Use in the Professional Car Wash Industry and Car Wash Association." p. 47.
2 Mid-Atlantic Carwash Association Inc. Information provided to the Maryland Water Conservation Advisory Committee. June 2000.
3 WaterWiser. February 2003.
4 Assumes a 15-minute car wash with flow of 10 gallons per minute.