I just started reading the oilguard website to learn about it. It shows to be "third party tested". Funny thing here, I used to work for Fluid Technologies, Inc the folks that did the testing. Nothing better than an inside connection for good information! They are just down the road.
http://www.oilguard.com/Merchant4/m...m&Product_Code=EPS-20-DC&Category_Code=dodge1