Diesel Engines 101

Click to ExpandDiesel Engines

Diesel engines are high-powered, highly efficient compression-ignition engines used in most industrial sectors in some capacity. At Central Diesel, Inc., we bring the advantages of diesel to customers in construction, marine, automotive, industrial, military, railroad, agriculture, government, mining, and more. We proudly supply premium diesel engines and components alongside comprehensive repair and rebuild services.

What are Diesel Engines?

Diesel engines are distinct from gasoline engines in two primary ways:

  • Diesel engines are powered by diesel fuel rather than gasoline
  • Diesel engines rely on compression ignition rather than spark ignition to combust fuel

Diesel fuel consists of heavy hydrocarbons distilled from petroleum, rather than the more volatile crude oil distillates used to create gasoline. While these heavy distillates evaporate at a higher temperature than gasoline molecules, they also have a lower self-ignition temperature than gasoline. Accordingly, diesel fuel does not require a spark to ignite. Instead, diesel engines compress the air in the compression chamber until it reaches a very high temperature, at which point the fuel enters the chamber and combusts.

Diesel engines are best known for their impressive efficiency. Spark-ignition engines, though theoretically more efficient than most diesel engines, are limited by the potential for pre-ignition at high compression rates. By contrast, diesel engines use very high compression ratios to induce extreme temperatures and combust the diesel.

Additionally, diesel engines take only air into the chamber on an intake stroke, rather than an air-fuel mixture. As a result, diesel engines do not require intake throttling to control power, so they are more efficient when idling than spark-ignition engines.

How Do Diesel Engines Work?

Close up of nozzles in diesel engine under opened bonnetFrom the operator’s standpoint, diesel engines function much as gasoline engines. However, the internal combustion processes are very different:

  • Once the key turns in the ignition, the engine begins to build heat by taking in air and compressing it to a high temperature.
  • When the engine is warm enough, the engine can be activated – typically by turning the key all the way to “Start,” and potentially by stepping on an accelerator.
  • This action triggers the fuel pumps to send diesel fuel through cleaning filters and toward the injection pump. The filters ensure that there is no particulate matter in the fuel that could clog the injector nozzles.
  • The fuel injection pump forces the fuel under high pressure into a delivery tube, which feeds the fuel into the fuel injectors. Finally, the injector nozzles spray the fuel into the combustion chamber.
  • Thanks to the effects of air compression, the temperature within the combustion chamber is such that the diesel fuel reacts with oxygen, causing combustion.

Advantages of Diesel Engines

A classic fragment of diesel car engine or truck engine with copy space for text. Metallic background of the internal diesel truck engine or car engine.Diesel engines offer efficient, powerful, and cost-effective performance in virtually any industrial setting. The key advantages of diesel engines over gasoline engines include:

Fuel-efficiency and cost. The design of diesel engines ensures superior fuel efficiency compared to gasoline engines of the same size, which leads to substantially lower operating costs over time. Even in markets where diesel costs slightly more than gasoline, diesel engines offer a great enough fuel efficiency difference that they still cost less to run in the long-term.

Engine durability. Diesel engines eliminate spark plugs, which are one of the most common failure points of traditional gasoline engines. Without spark plugs, diesel engines can often go longer without requiring maintenance or repair. Additionally, diesel engine components tend to be sturdier overall, given that they must withstand extreme compressive forces. Combined, these factors mean that diesel engines offer incredible return-on-investment (ROI) even before accounting for lower operating costs.

Cold-weather performance. At very low temperatures, spark plugs may have trouble igniting — especially those that are old or otherwise damaged. Since diesel engines don’t rely on spark plugs, they never encounter this problem. Moderately low temperatures are no problem for the modern diesel engine, although extreme cold may cause diesel fuel to become gelatinous as paraffins stiffen in the fuel. Winter-mix diesel fuels solve this problem by incorporating hydrocarbons with a lower freezing point, so diesel engines remain the better choice if cold-weather performance is a concern.

Greater torque. As a result of their higher compressive forces, diesel engines produce significantly more torque than gasoline counterparts, making diesel the better choice for heavy-duty industrial applications.

Industries & Applications of Diesel Engines

Diesel engines are sometimes found within commercial passenger cars, although this is not as common within the United States. More frequently, diesel engines power large, heavy industrial vehicles that benefit from the additional power and torque. These applications include, among others:

  • Railroad locomotives
  • Marine vehicles
  • Construction vehicles
  • Farming equipment
  • Heavy duty trucks

Diesel engines also power generators for portable power generation, as well as for emergency back-up power. Applications in this context include:

  • Mining generators for excavating machinery and drills
  • Backup generators in hospitals
  • Oil and gas generators for powering remote drills
  • Portable generators for military personnel
  • Lighting generators for construction crews

Some industries that make heavy use of diesel – whether in the form of diesel-powered vehicle engines or generator engines – include the following:

  • Agriculture
  • Construction
  • Industrial manufacturing
  • Marine
  • Mining
  • Transportation

In all of these fields, diesel provides a reliable, high-performance option for generating power exactly where and when it is needed the most.

Diesel Engine Products From Central Diesel

Repairing of modern diesel engine, workers hands and tool. Car mechanic looking at engine for analysis symptoms of car at maintenance repair service stationAt Central Diesel, we understand the central role that diesel engines play in countless industrial workflows. We offer a comprehensive range of products and services designed to help our customers make the most of their diesel engines.

We are proud to be an authorized distributor for both Deutz and Mitsubishi Industrial Engines, which offer top-of-the-line performance in even the toughest industrial settings. Additionally, as certified dealers, we are qualified to repair and service the following brands:

  • Cummins
  • Isuzu
  • Perkins
  • Hatz
  • Kubota
  • Kohler
  • Lister-Petter
  • Lombardini
  • Continental
  • FTP
  • Vanguard/Briggs & Stratton
  • Ingersoll Rand

We also offer full-service installation, maintenance, and repair for diesel engines, and we stock a diverse array of components for replacements, repairs, and upgrades:

  • Filtration systems
  • Fuel injection systems and components
  • Hydraulic hoses and fittings
  • Electrical components for diesel engines
  • Exhaust systems
  • Turbocharger assemblies for diesel engines
  • Diesel generators
  • Railroad systems and components

Since our founding in 1972, we’ve helped thousands of customers identify and meet their diesel needs. To learn how Central Diesel can do the same for you, contact us today or request a quote.

Diesel vs. Gas Engine: Life Expectancy, Emissions, Efficiency


When comparing diesel and gasoline engines, diesel engines are ultimately considered superior to gas engines in heavy-duty vehicles because of their improved fuel efficiency and longer life expectancy. They are often the preferred engine type for vehicles such as emergency vehicles, bulldozers, dump trucks, excavators, ships, semi-trucks, and trains.

Diesel vs Gas Engine

Diesel vs Gas: Understanding the Differences

Though both diesel and gas engines are internal combustion engines, there are differences in their operations that make diesel engines more suitable for industrial vehicles. The differences come from:

  • The higher energy density of diesel fuel
  • The greater compression of air by diesel engines
  • The absence of spark plugs in diesel engines


These differences contribute to the following characteristics:

  • Life expectancy. Diesel engines compress air almost twice as much as gas engines (approximately 20:1 vs 10:1). As such, engine parts like block and cylinder heads, crankshafts, pistons, and valves in diesel engines are designed to be more robust than gas engines. This higher compression also results in more complete combustion of the fuel than what is found in gas engines, so diesel engine exhaust is less corrosive. This contributes to a longer service life for engine components.


  • Fuel costs and efficiency. Due to increased air compression, diesel engines also operate at higher temperatures than gasoline engines. This results in a more efficient conversion of thermal energy to mechanical energy. Diesel engines are about 15–40% more efficient than gas engines and diesel fuel is about 15% cheaper than gasoline. Therefore, the per-mile cost of diesel engines is significantly lower than gas engines.


  • Torque/horsepower. The high compression ratio of diesel engines gives them an ability to create a higher torque at lower engine speeds. Also, diesel fuel has 12–16% more energy content than gasoline. These factors make diesel engines ideal for heavy load applications that require a steady, high torque.


  • Maintenance costs. Diesel engines do not have spark plugs. Diesel is also a much better lubricant than gasoline. When considering emissions from diesel versus gasoline, the more complete ignition of the diesel fuel produces less pollutants and corrosive agents. Diesel engines operate at a lower rpm than gas engines. All these factors contribute to reducing the maintenance costs for diesel engines.

Diesel EngineGas Engine

The Importance of Proper Engine Maintenance

Diesel fuel easily picks up contaminants due to its high viscosity. Periodically changing the oil and oil filter will clean accumulated dirt from inside the engine. It is also important to keep an eye on oil consumption as an early indicator of harmful oil leaks. These should be quickly detected and promptly fixed.

Diesel engines require a steady supply of clean air to maintain peak performance. Dirty filters reduce airflow to the engine, so it is important to regularly inspect and change air filters. This is especially important for dump trucks, military vehicles, and boats that operate in harsh environments.

Quality Diesel Engine Services from Central Diesel

Central Diesel offers troubleshooting and restoration services for damaged or malfunctioning diesel engines. Our experienced staff can help you to identify and correct problems with your diesel engines before they result in engine failure and costly replacement.

We are a diesel engine specialist and have been supplying parts and providing maintenance services to government agencies, the military, and heavy industries like mining and agriculture for over 45 years. Please contact us or submit a request for a quote for assistance with your diesel engine maintenance and repair needs.

Give Your Security Team a Boost with Mobile Safety Products

Over the course of June – National Safety Month – the National Safety Council raised awareness of the most common causes of injury and death in the workplace and helped companies develop effective strategies to ensure the safety and health of their workers. As a proud supporter of National Safety Month, we wanted to take a moment to further that mission by sharing some of our safety solutions with our customers.

How Can You Improve Workplace Safety?

Workplace safety should be a leading priority for any company, but it doesn’t need to be a challenge. Taking these simple steps can help you keep your workplace is as safe as possible at all times.

1. Follow OSHA Guidelines 

The Occupational Safety and Hazard Administration (OSHA) was founded to protect American workers from harmful conditions by establishing safety standards for every major industry and educating businesses on the best practices for their workplaces. Regardless of your field, be sure to acquaint yourself with any relevant OSHA regulations and follow them as closely as possible.

2. Post Signs, Labels, and Warnings throughout the Workplace

Workplace accidents are usually the product of carelessness or ignorance rather than deliberately unsafe behavior. Outlining the precautions that employees need to take before entering a certain space or handling a particular piece of equipment can significantly reduce the risk of injury or death on the job.

3. Employee Training and Certification Programs

At the end of the day, the best safeguard against occupational hazards is a well-informed staff. All employees should receive thorough instruction in any tasks or processes in which they’re involved, and any functions that could endanger the entire workplace if performed improperly should be limited to employees with special certifications.

Mobile Safety Products to Add to Your Worksite

While these common sense measures can improve safety throughout the workplace, recent technological innovations can prove an invaluable addition to your company’s safety procedures. At Central Diesel, we’re pleased to produce a number of mobile safety products that can further strengthen your efforts to protect your employees.

Our mobile safety solutions are designed to shore up your safety strategies wherever necessary. Our Mobile Surveillance System, for example, constantly monitors any space that requires heightened visibility, helping you ward off intruders or unauthorized employees. Similarly, our Mobile Lighting Systems can increase visibility in any environment in which light is limited, eliminating a common cause of workplace accidents.

Following National Safety Month, it’s an ideal time to review and modify your safety strategies as necessary. Take the time to thoroughly assess your operations and speak with employees to identify possible risks and develop effective solutions to them. From conducting necessary trainings to investing in appropriate safety equipment, don’t hesitate to make needed changes.

At Central Diesel, we’re committed improving American companies with cost-effective safety products that provide lasting protection from any occupational hazard. If you’d like to explore our offerings, contact us today.

Recognizing Industry Contributions for National Manufacturing Day 2017

Even though experts believe that two decades of policy failures have stagnated the growth of the US manufacturing sector, it is still active enough to employ 8.8% of the national workforce and taken alone would be the ninth largest economy in the world. But if the golden era of manufacturing is to return to the shores of the country in earnest, a lot more than just infrastructural expansion and demand generation would have to be taken into account.

While the next eight years will see about three and a half million new jobs added to the sector, sadly two million of these vacancies will go unfilled.

There is hope for the future but to usher it in the United States needs more students interested in S.T.E.M careers, better knowledge transfer between employees, and a revamped perception of what careers in manufacturing are like in 2017.

The National Manufacturing Day (NMD) – a nation-wide endeavor undertaken the first Friday of every October attempts to hit the goals above.

Annually celebrated on the 6th of October, we’re taking a look at the impact of NMD and the contribution of our industry to manufacturing as a whole.

What Has the National Manufacturing Day Achieved?

Over the last six years, the National Manufacturing Day has seen the participation of hundreds of thousands of suppliers, manufacturers, and students. More than 2,100 factory tours have been organized, and in 2017 it is expected that 600,000 businesses and individuals will be associated with the event.

Thanks to the impact of NMD and a closer look at the changing face of American manufacturing careers, 81% students are more convinced that manufacturing can provide them with stable, interesting and well-paying jobs.

89% are also more aware of manufacturing opportunities in their communities, and 64% are more likely to pursue them.

Diesel Engines: Igniting the Manufacturing Spark

Almost all industries that are a part of the manufacturing sector look back at what businesses have achieved over the years when the National Manufacturing Day rolls around.

The diesel engine market is billions of dollars strong in the US, heavily contributing to both the manufacturing sector and the economy. With the Diesel Emissions Reduction Act, this number is only going to increase.

Moreover, without diesel engines, all aspects of manufacturing from the actual production of goods to their transportation suffer because other combustion set-ups consume more fuel, produce lower torque and are far less durable and resilient than their diesel peers.

Diesel engines save the manufacturing sector millions every year in maintenance and repairs.

A Word on Central Diesel

Central Diesel Inc. with its premier fuel injection systems, parts, and custom services is proud to chip in when it comes to providing these advantages.

This National Manufacturing Day visit our facility in Richmond and allow us to show you how we innovate on the job and boost customer satisfaction.

Want to look at our catalog? Call us at 800.598.9814. You can also follow us on Twitter and LinkedIn for the latest industry updates.

Happy National Manufacturing Day 2017 from the Central Diesel team!