The paper presents an overview of the U.S. commercial and military diesel fuel quality. When coupled with yesterday's fuel handing technology and out-of-date systems, the problems of tomorrow are born. Tomorrow's safety and maintenance problems are discussed and some potential problem solutions are offered. The only real comprehensive solution would be to invest in the necessary onboard protective treatment equipment and to properly operate this equipment.Tomorrow's maintenance problems will be increased starting problems, increased bore and ring wear and corrosion, more bore deposits and turbocharger fouling, more injection pump and injector corrosion, fouling and sediment damage, more micro biological problems, more tank storage sludge problems, and more filter/coalescer problems.The future's more volatile, more aromatic diesel fuels will add to the concern for exhaust gas toxicity. The increased aromatic content can compromise storage stability as well as thermal stability.