Emulsifier vs. Demulsifier: How Should Diesel Additives Handle Water?

Water in diesel fuel is a serious concern. It can contribute to corrosion, filter plugging, microbial growth, injector problems, and fuel system wear.

What Is an Emulsifier?

An emulsifier helps disperse water into the fuel so it remains suspended. Some products use this approach, but it can carry water farther through the fuel system.

What Is a Demulsifier?

A demulsifier helps water separate from the fuel so the fuel/water separator can do its job. This approach is commonly preferred by many diesel engine and fuel system manufacturers.

Opti-Lube’s Approach

Opti-Lube diesel fuel additives are designed to support water separation. The goal is to help water drop out of suspension so it can be removed by the vehicle or equipment’s water separator rather than carried through the fuel system.

Best Practice

Keep tanks as clean and dry as possible, drain water separators as needed, and use a fuel additive that supports the way your fuel system is designed to handle water.

Need help choosing? Start with Opti-Lube diesel fuel additives or review our FAQ for dosing, storage, and compatibility questions.