ABSTRACT
Overbased detergents are commonly used in automotive and marine lubricants. Their main functions are to neutralise potentially corrosive acids and to contribute to engine cleanliness. The major types of overbased detergents that are produced commercially are phenates, sulphonates and salicylates. This paper will describe the chemistry of these additive classes and review their properties and performance in bench and engine tests. The paper will also describe a new class of overbased detergents. Novel chemistry has been used to produce new types of highly overbased phenate, sulphonate and salicylate. These new products exhibit significant improvements in properties and performance over conventional detergents. Evidence from bench and engine tests will be presented to demonstrate the benefits of the new detergent types.
