A couple things have happened to change the french fry oil usage in diesel engines. First, as already stated, the restaurants are "selling" the used oil, second, restaurants were having problems with the general public wanting the oil and then making a mess when they were taking it, and finally in California and perhaps other states, it has become illegal to "transport" used oil in larger quanities unless you have a license to do so. So it came down to who makes a profit, the restaurant or the government.
2001 National Tradewinds 7370 300 Cat
2011 Jeep Wrangler Unlimited Sport
Officially fulltiming. The Journey Begins