Your warranty can be voided simply by using incorrect or contaminated Diesel Exhaust Fluid (DEF). Be sure to use the correct DEF designated for your vehicle, as different trucks have different specifications. Correctly stored DEF has a shelf life of around 18 months. This means it should be stored in temperatures above 77 degrees F. Temperatures above this will significantly reduce its shelf life, wasting your time and money. You should watch for water, dirt, and other contaminants which will ruin DEF and void your warranty as well. With the importance of the SCR system in today's vehicles, DEF has taken on a greater role in your trucks maintenance. It is important to keep your truck running smoothly and avoid inadvertently voiding your warranty over an issue such as DEF.