Diesel exhaust fluid, better known as DEF, has become a normal part of owning a modern diesel truck. But according to the American Petroleum Institute, many diesel owners still misunderstand how DEF works, how it expires and how using contaminated fluid could lead to expensive repairs. In this Q&A interview, API’s Jeff Harmening explains why DEF quality matters, how improper storage can damage emissions equipment and why stocking old DEF in your garage may not be the money-saving move many truck owners think it is. You can watch the video interview as well. Why Does DEF Need To Be Certified? Q: […] (read full article...)