3 min 30 sec is our $12.00 washes time from when the pre-soak starts to when the dryers kick on. With our 3 other washes we average 18 cars an hour. while one car is drying, the second cars wash is beginning. 2 cars in the bay at the same time. One getting pre-soak the other drying. We have wind walls in the tunnel minimize the dryers blowing the pre-soak around to much.
Yeah, technically i'm sure we could have created our set-up with 15-20 feet. But we went with an additional 25. That is actually how Oasis recommends setting up there wash equipment. They sell a drying system that creates a 2 part wash. 1st step washing 2nd step drying. It creates a much higher wash count compared to having cars slowly pull through the dryers as the next customer waits. If the car drying is not out of the way, the next customer in line wont pull into the bay. If you have a 60 second dryer cycle then that basically slows down each wash by 60 seconds because the car waiting is not able to proceed into the bay to being there wash.
See link
http://oasiscarwashsystems.com/eclipse/
Instead of buying oasises drying system we chose to to add the 25 feet but put in our own drying system. We went with with premier dryers, and they work good. We thought our customers would prefer driving through stand alone dryers vs parking in the 2nd half of the bay and waiting for Oasises dryers to dry there car. Because even though we give 60 seconds of dryer time there are always people that only use about 15 seconds and then drive off fast. Our customers ultimately want a fast quality wash with good value not unlike all of your customers as well. So, With the typhoon with an extended bay we can offer that.
We don't always need that kind of wash volume as are wash is in a Fairley rual town, only about 5,000 people. But after those big snows, and when the sun is shinning and the streets are dry and you have lines all day. You are thankful for that speed. Lots of ways to set up your car wash, but that is just what we have found that works for us, unless you would just rather invest in a tunnel which we didn't care to do.