How much soap

Interesting question, you're mixing a bucket of soap and water to wash your car and you want to know how much soap to use. Well, it depends, the dirtier the car, the more soap you need. The only way to really know is to watch the suds. The suds are there to let you know if there's still cleaning power left. Add the amount of soap to your bucket of water that feels right to you. As you wash the car, pay attention to the suds. If they go away and blasting the bucket with a hose for a second doesn't bring them back, you didn't add enough, if after you're done washing the car it seems like there are more suds than you started with, then you could have used less. After a few times you should be able to figure out how much soap your bucket of water needs. The recommendation on the Z-7 bottle is 2 or 3 capfulls per gallon and I wouldn't recommend you mix much more than 2 gallons at a time or you waste a lot of car wash.