Fuel Lubricity Requirements for Diesel Injection Systems

Abstract
The U.S. Department of Defense has adopted the single fuel for the battlefield concept. Diesel fuel will be replace by JP-8/Jet A-1, which has both lower lubricity and viscosity. Currently, the tribological requirements of fuel- lubricated components in the injection system are unknown. As a result, no widely approved lubricity test or standard exists. Similar problems are currently faced in commercial applications where low-sulfur/aromatic fuels are bring introduced. The present study details the wear mechanisms likely to exist with low lubricity fuels, with particular reference to injection equipment known to be fuel sensitive. The wear mechanism was found to ba a function of contact severity and may not be uniquely defined by a single test. A number of potentially viable lubricity tests is suggested, and fuel/additive components are recommended for wear reduction.