Exhaust emission standards threaten the viability of diesel engines for future urban bus applications. Engine design modifications alone may be insufficient to meet impending standards. Consequently, various exhaust after treatment and/or alternative fuel options are also under study. To some degree, all of these approaches affect lubricant performance requirements. The potential for enhancement through accommodative changes prompted investigation into the positive and negative effects of lubricant variables on diesel exhaust emissions. This work demonstrated that broad chemical latitude exists to meet the needs of modified engines. In the case of after treated designs, strong potential is shown for chemical fuel supplements to provide auto-regeneration of passive particulate collection systems. (A)
Abstract