Mobil Delvac™ lubricants are formulated with a balanced additive system to provide outstanding performance for equipment. We invest millions of dollars testing our formulations to ensure this performance. Use of an aftermarket additive can easily throw this balance off, potentially causing severe problems. Additionally, many equipment builders now state in their service manuals that they specifically recommend against the use of these aftermarket additives. When you make a decision to purchase Mobil Delvac products, you can rest assured that they are formulated to provide optimal lubricating performance without any need for additional additives.