I "winterized" our Pleasure Way Pursuit yesterday. I drained the water tank down to about 8 gal. and poured 3 gal. of RV anti freeze into the tank. Then I ran all the sink faucets both hot and cold, ...
I noticed that all these responses are from cold climates where the issue is more serious. I found this chart: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0073/0901b80380073445.pdf?filepath=heattrans/pdfs/noreg/180-01530.pdf&fromPage=GetDoc It says a 12% solution of antifreeze protects against bursting down to 20º F. Even a 5% solution lowers the freezing point to 29º. I'm satisfied with what I did.