Engine manufacturers and their engineer teams have put a great deal of thought and money into reducing emissions in recent years. As limitations, particularly in the U.S. and Europe became more stringent, the engineers tuned the engine design with everything from electronic injectors to redesigned combustion chambers. Further mandated reductions in emissions are anticipated. Some operators are not waiting for the regulations but are going to the next level with the aid of independent suppliers. The diesel-electric Stril Mariner is a good example.