New deposit controlling additive technology has been identified and successfully evaluated in a heavy duty diesel (HDD) engine. This additive technology was selected on the basis of a screening protocol that has been developed to enable the identification of chemistry effective in controlling HDD piston deposits. Caterpillar 1N engine test results have confirmed the efficacy of the deposit controlling additives, thereby validating the screening protocol. The deposit controlling additives function by targeting the inception of the deposit forming mechanism. Such an approach is directed towards the concept of deposit prevention as opposed to providing a remedy subsequent to deposit formation. Emissions regulations and their impact on lubricant formulation is also mentioned together with industry requirements and methods for assessing the control of piston deposits. The additives that have been identified together with the screening approach that was developed, will provide a foundation for addressing the technical needs of future HDD categories, such as PC-9, where piston deposit control is a requirement.