Diesel Exhaust Fluid (DEF) plays an important role in moderating truck emissions and meeting EPA guidelines. As with any type of vehicle fluid, regular monitoring of DEF levels is an important part of ongoing maintenance. While checking diesel exhaust fluid levels isn’t a difficult job, there are factors that can complicate the issue. Here’s everything you need to know! 🔥 #FosterFuels #FosterGoesFurther #DEF #DieselExhaustFluid | Foster Fuels