I had a good friend who was a darn good shade tree mechanic. He used recycled oil and rolls of toilet paper for filters in his cars and trucks. I don't recall him having any problems as result, but he could never convince me to try it.
Had a buddy in high school whose entire family fleet used the Frantz oil cleaner systems with the toilet paper inserts.
I haven't thought about them in years. I was shocked when I just did a websearch and found they're still available!!!
History:
The Frantz Filter was invented by John Frantz, of Hickman, California in the 1950's. He was a Farmer responsible for several hundred acres of land; his primary crop was Walnuts. John was a very hard working, conservative, and honorable Man. It was said that one day he had a container of used motor oil from one of his tractors and rather than throwing it away, he tried to come up with away to see if he could clean up the oil for reuse. He tried several different medias to try to clean or filter the used oil. One idea was a clean coffee filter. One day, he experimented with a standard roll of Toilet Paper.
In the beginning, they were called the "Frantz Oil Cleaner." Later on it was called the "Frantz Oil Filter." In the early 1960's, John Frantz was introduced to Skipper K. Yee who had a vast knowledge of marketing. SKY Corporation was formed and for almost 20 years, the Frantz Filters were manufactured out of Stockton, California. Frantz Filters were also designed to clean/filter other petroleum products including Transmission Fluid, Gasoline and Diesel Fuel. As SKY Corporation grew, there were thousands of Distributors and over a million Frantz Filter systems manufactured and sold throughout the United States & around the world. There was a variety of sizes and styles also available. In the late 1980's, SKY Corporation located in Stockton, California went out of business.
