The diesel engine is a constantly evolving machine. Since its inception in the late 18th century it has changed countless times to better suit the needs of industry. Diesel engines have the highest thermal efficiency of most standard internal and external motors and can last for decades with proper maintenance and care. To understand the heavy trucks of today it’s important to know how the diesel engine evolved from stationary industrial applications to the efficient motor that drives today’s economy. Knowing the history will also help predict where diesel engines will be in the future and the overall direction of the industry. In the early stages of the diesel engine’s development, power was the main metric for success. It isn’t until recently that fuel efficiency and emissions have become a serious issue. Many of the first engines emitted large amounts of harmful chemicals into the environment and, when multiplied by tens of thousands of trucks, the impact was severe. Many states, such as California, are pushing for more and more efficient engines with less and less emissions. California publishes their compliance guides and regulations here on there website but sometimes locating this information from state to state can be difficult. If you own a truck or fleet of trucks make sure you are up to date with your state’s current requirements.
The history of the diesel engine starts with it’s namesake, Rudolf Diesel. In 1885 Diesel began construction of the first prototype of the engine in Paris, France. At the time, steam power was the predominant source of locomotion and had Diesel not shown his engine’s merits we might be driving giant, steam-powered big rigs. Diesel’s engine, after a few years of modifications, showed a 26.2% rate of efficiency blowing out the current steam engine’s of 10% (Source.) From there, the engine quickly made its way into industrial equipment and locomotives and in 1923 companies MAN and Benz created the first truck with a pre-chamber diesel engine. Injection engines and two stroke engines quickly followed and by 1938 GM had formed what is now known as Detroit Diesel and Caterpillar had started making diesel engines for their tractors.
Fun Fact: In 1932 the strongest diesel truck in the world operated at 160 horsepower. It would be hard to get anything done with that today!
In 1956 the Federal Aid Highway Act was passed allowing construction of today’s interstate system of commerce. The interstate system allowed for large, powerful trucks to be manufactured and utilized, greatly increasing the efficiency at which goods were distributed throughout the country. The interstate system was loosely based on the German autobahn and serves many purposes other than the transport of freight and passenger vehicles. In a time of war the interstate can even act as a landing strip for military planes. During the sixties and seventies turbo-diesels ruled the road and gas-guzzling semis were the norm. It wasn’t until the price of gas began to skyrocket and after the Environmental Protection Agency’s formation and subsequent rise to authority that stricter fuel and emissions regulations began to form.
Fun Fact: Double digit interstate roads are considered “primary” routes and triple digit roads are considered “auxiliary roads”. So if you are on a triple digit interstate road you are probably going around something important.
Now, in the age of electronics and four dollar gallons of gasoline, efficiency is taking precedent over power. With today’s manufacturing technology, engines can be tremendously powerful while still minimizing emissions and fuel consumption. We covered, in an earlier article, how a Cummins engine was able to maintain a 13.4 MPG average in a revenue producing trip pushing the limits of fuel efficiency. Comparing this to the 1970’s Peterbilt 359 averaging under 5 MPG it is a tremendous gain in cost savings and environmental impact. Certain baseline requirements are set by the government, such as DPF (Diesel Particulate Filter) boxes, but for the most part, a truck owner’s fuel consumption is largely dependent on the management and purchasing decisions they make. Programs like MyGauges.com allow you to monitor a truck or fleet of truck’s performance digitally and electronic on board recorders (EOBRs) can track engine temperatures, mileage and malfunctions and owners can use this information to fine tune their truck’s engines. The diesel engine has become a sophisticated machine that takes feedback from all parts of the vehicle. As we move towards the future in the commercial trucking industry, engines will continue to adapt to the needs of the market. Truckers will continue to try and push the diesel engine further and further, getting every last bit of horsepower and piston stroke they can from these wonderful machines.