Question: how much water is used to wash car?
Answer: Water — Who Uses How Much? Vehicle washes use a fair amount of water. Some friction in-bay automatic systems use approximately 35 gallons per vehicle, and a high-volume in-bay site could average 100 cars a day — that's 3,500 gallons a day, 105,000 gallons per month, or 1.26 million gallons per year.