Good luck finding any. All sources of WVO seem to be gobbled up by the large rendering companies paying the restaurants as much as $3.00 a gallon for used oil and selfish "co-ops" taking all sources. Restaurant owners think it's worth the price of gold these days as well so when you go and try to inquire about their oil they seem to get all asshole on you about asking.
Restaurants use to have to pay to get rid of the oil, now they are getting paid for it. Some rendering companies depending on location pay more than 2 dollars a gallon. What more "data" do you need. How much oil have you collected in your life?And how do you know this? That is my question.. what empirical data do you have to support that claim.
http://http://www.ams.usda.gov/mnreports/lswagenergy.pdf.All I want is a reputable source of information.