Diesel engine sales are up for 2004. Markets buying diesel
engines at a record pace include trucking companies, the
agriculture industry, heavy industry, and even consumers who are
tired of the paying a high price for gasoline for their trucks
and SUVs. But the continued success of diesel engines also
magnifies a pollution problem that diesel engine companies have
been scrambling to solve.  EPA regulations  The EPA says that
long-term exposure to diesel fumes is likely to pose a lung
cancer hazard and that the particulate emissions from diesels
are associated with increased risk of heart and respiratory
problems. The agency has instated an aggressive, multitiered
schedule of regulations designed to force the diesel industry to
produce cleaner engines.  With sales on the line, diesel engine
companies like Cummins realize that they can't afford not to
meet EPA regulations on time. Caterpillar, another of the top
diesel engine players, recently celebrated its success with its
Advanced Combustion Emissions Reduct