We use the flashpoint test to determine fuel and how much is present in used engine oil. This test has deep roots in the history of used oil analysis at large, and Blackstone's personal history. If you're interested in uncovering fuel dilution or tracking down a fuel system issue, this episode gives the breakdown of fuel testing and how the entirety of the standard analysis tells you about how contamination might be impacting the engine and oil itself.Episode Guide: Listener Appreciation Segment (1:58)Slick Talk T-shirts! (4:15)Flashpoint definition (5:40)How to find a flashpoint (8:45)Fuel testing in the 50's (10:50)Importance of additives (14:40)Is it a problem to sample cold? 19:00