If I use 42,000 gal / 3gpm = 14,000 min ---> 14,000 * 0.25c * 50s / 60s = $4,200. How did you get to $5000? A little more detail I've learned ... bay functions are Tire/Engine Cleaner, Rinse, Soap, Wax, Foam Brush, Spot Free. Current owner is using 1 - 5GAL bucket of Tire cleaner, foam, and...