I am a mechanical engineer. I received my Bachelor's degree from the University of Michigan-Ann Arbor in 1993. Thereupon, I began full-time employment with Detroit Diesel in the diesel engine business. Two years later, I resigned Detroit Diesel and joined another company's engine division and continue to be employed there to this day.
Engineering is a creative occupation in which engineers design useful things that people are willing to pay money for. In a very real sense, engineers design the things that make the world go around. My career in engine engineering has involved mostly the design of engines or the application of engines into vehicles. I had roles in manufacturing and purchasing.
During the past two decades, the vast majority of the activity in which I have been involved has been related to meeting exhaust emissions regulations. My work has involved making the necessary changes to the internal parts of the engine (e.g., pistons, valves, cylinder heads, and so on) to make them compatible with the performance changes that were made to the engine in order to meet emissions regulations or other requirements. This type of work can be reduced to three basic areas: design, testing/experimentation, and problem solving.
As an example, for a number of years I did work on the valvetrain portion of the engine. This part of the engine is responsible for allowing air and fuel into, and exhaust out of, the engine. Valvetrain components are sensitive to the pressures and temperatures inside of the engine and are made of highly precise and relatively expensive materials. Emissions regulations and performance requirements (e.g., more power, better fuel efficiency) generally cause the temperatures and pressures inside the engine to go ever higher and higher. This presents the challenge to the engineer of improving the capability of the internal components while still making them affordable.
The process works as follows. The customer or government regulating body (e.g., EPA) establishes criteria that the engine must meet in order to be sold for a particular application, say a bulldozer. Performance engineers will tune the engine in a test cell until the engine meets the new criteria. This often requires extensive changes to the fuel system, air system and other systems on the engine. It is then the job of the engine component engineers to make certain that the rest of the engine will work under the new operating conditions. Essentially, a new component is designed, tested, and refined until it meets all of the requirements of the customer and the business. My role in engine engineering has been to repeat this process for successive changes in requirements.
In a typical scenario there will be dozens of engineers working in an office environment on just one part of an engine or machine. These engineers, myself included, spend most of their time at their desks in front of a computer. Their fundamental task is engineering design work using Computer Aided Design (CAD) software or simulation and analysis software. These tools are used to develop and evaluate a design in its initial stages. This early stage of design may last months or years depending upon the complexity of the activity. The engineers will also spend a good deal of time managing their projects and interacting with other engineers and support groups in person or via telephone, email and other electronic means.
Again, this example pertains to just one part of an engine or machine. Taken as a whole, there are literally thousands of engineers, generally in groups of dozens or hundreds in a particular location, across the corporation (and the globe). All of these engineers will be working toward the same basic goal. That is, redesigning an engine or machine to meet emissions criteria, or other criteria associated with a particular product development program. To get a sense for the annual labor cost associated with this type of activity, let's use a simple example. Let's assume that there are a total of five thousand engineers working on an emissions program and that the average cost of an individual's wages and benefits is $100,000 annually. Just these labor costs alone would equate to half-a-billion dollars annually. The actual total cost of this activity is greater than this and peaked at around two billion dollars per year during a recent emissions update program.
A particularly aggressive set of requirements over the past two decades or so have been those that have been imposed by the Environmental Protection Agency (EPA). Beginning in the late 1980s, EPA set about to "reconcile the diesel engine with the environment." Regardless of your political views on the issue, from the outset it was clear that the intention of the EPA was to make the "dirty diesel engine" extinct. From that time until now, there have been successive and ever-tightening levels of regulation placed upon diesel engines and powered machines every 3-5 years. From 1996 until 2014, regulated exhaust constituents such as particulate matter ("soot") and oxides of nitrogen will have been reduced by 96 percent. That is, at the end of 18 years of regulation-driven changes, the total emissions level (of particulate matter and oxides of nitrogen) will be at just 4 percent of their previous levels. It has been shown that for some exhaust constituents, the air coming out of the exhaust pipe is actually cleaner than the air going into the engine.
So, here we have a 96 percent reduction in diesel emissions balanced against a cost of at least the billions of dollars, for just one company. The total cost would multiply many fold across the entire industry. The stated benefit to society has been measurable and significant reduction of diesel engine emissions in the air we breathe. Exactly how much this affects the health of people and the planet is a question best left to those who specialize in such things. I have provided the reader with an idea of the challenge and cost of achieving such regulatory goals. *