Natural gas (CNG) vs. LPG, LNG, RNG and Diesel

Gas pump

Commercial vehicle fleet managers face a dizzying array of options when it is time to replace or upgrade vehicles. One question that fleet managers often ask is whether there are any good fuel options available to their business besides diesel or gasoline. Alternative fuels, including natural gas, have grown in popularity in recent years due to their broad appeal. Considering a full or partial switch to an alternative fuel is more often than not a question worth asking. Here is how the main fuel options compare to each other.

Compressed Natural Gas vs. Diesel

Natural gas is a great choice for many types of heavy and medium-duty vehicles because it burns cleanly. Anyone who has replaced an oil furnace with a natural gas furnace in their home knows this. Oil furnaces produce soot and must have their flue cleaned regularly. Natural gas furnaces, in contrast, can be vented through the side of the house. You will never see any trace of soot on the wall above the vent because the combustion of natural gas doesn’t produce any. It’s the same thing with natural gas vehicles—they don’t generate particulate matter or volatile organic compounds (VOCs), and they don’t require difficult to maintain exhaust treatment systems. Beyond the environmental aspects, the benefits of natural gas engines are reliability and financial.

If interested, don’t forget to dive deeper in natural gas engines vs. diesel engines.

Natural gas vs. LPG

LPG, or liquefied petroleum gas, is a mixture of light hydrocarbons. In the U.S. and in Canada, LPG consists of at least 90% of propane, with the balance made up of other gases including butane. This is why LPG is sometimes simply known as propane. In other countries, the composition of LPG can vary. In Mexico, for example, LPG’s propane content can be as low as 60%.

Natural gas, in contrast, is almost entirely made up of methane. If you have a gas grill, then LPG is what you use for your cookouts. If your home has a gas furnace, then natural gas is what keeps it warm (LPG or propane furnaces are also available).

In vehicle applications, LPG and natural gas present many of the same benefits. Both burn cleanly and silently, can help reduce maintenance vehicle costs, and can eliminate most cold weather start problems. LPG is the third most widely used motor fuel in the world behind gasoline and diesel, and so LPG tends to be easier to find. According to the US Department of Energy, there are almost 2,000 publicly accessible LPG fueling stations in the United States and Canada.

Compressed Natural Gas, in comparison, is only available at less than half that number of stations. (Both numbers are dwarfed by the number of gas stations dispensing gasoline, which is greater than 100,000).

Compressed Natural Gas vs. Liquefied Natural Gas

Compressed Natural Gas, or CNG, and Liquefied Natural Gas, or LNG, are the same substance. CNG is received and stored a vehicle’s tank is gaseous form. To obtain LNG, natural gas is compressed and cooled to extremely low temperatures, at which point it turns to liquid. LNG can then be shipped, stored, and used to fill the tanks of LNG vehicles. Much of the global natural gas trade occurs in the form of LNG. Some countries, such as South Korea and Japan, receive almost all of the natural gas they use in LNG form.

In vehicle applications, the main advantage that LNG has over CNG is that it is more dense. For two tanks of the same size, the LNG tank will allow a vehicle to drive further than the CNG tank. This makes LNG an interesting option for heavy trucks traveling long distances.

LNG, however, is more complicated to use, and is not widely available. LNG fueling stations require complex cryogenic equipment. There are only about 55 public-access LNG stations in the United States, and most are located at industrial facilities where natural gas is processed. LNG is also more hazardous than CNG. One safety concern results from the need for LNG vehicles to vent off fumes. LNG vehicles do not normally come with LNG cooling systems, so LNG tanks tend to gain heat. The heat gains cause some of the LNG to vaporize. Eventually, the vapors need to be vented to avoid excessive pressure build ups. This is why LNG vehicles should never be parked in interior garages unless special ventilation is installed. LNG, being very cold, can also cause freeze burn. Contact with LNG, LNG vapors and the uninsulated surfaces of LNG fuel system components should also be avoided, and drivers and mechanics need to be trained in LNG safety.

Natural gas vs. Renewable Natural Gas

Chemically, natural gas and renewable natural gas are almost identical. Natural gas vehicles can run on renewable natural gas without experiencing any difference. Natural gas and renewable natural gas differ in their origin. Natural gas, like oil, is extracted from fossil resources present in the ground. Renewable natural gas is obtained by fermenting organic waste such as sewage sludge or animal manure in large industrial tanks known as digesters. After some processing, the gases given off by the fermentation process can be used interchangeably with fossil natural gas.

Switching to renewable natural gas is a great way for businesses operating fleets of vehicles to reduce their carbon footprint. It can be produced at almost any dairy farm using relatively low tech equipment. It can be used to fuel nearly any CNG vehicle. If it is not practical to fuel a vehicle entirely on renewable natural gas, then blending with fossil natural gas is possible. Even then, the use of renewable natural gas will result in an instant reduction in CO2 emissions without the need to invest in any upgrades or modifications to the vehicle.

If natural gas engines are relevant to your needs, don’t forget to also check our answers to frequently asked questions about natural gas engines. These answers cover topics such as cost, practicality, and feasibility of integrating natural gas into commercial fleets.

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Puneet Singh Jhawar

Puneet Singh Jhawar

Puneet Singh Jhawar is the General Manager of the global natural gas business for Cummins Inc. In this role, he is responsible for the product vision, financial management and overall performance of the natural gas business. Over his 14-year career at Cummins, Jhawar has cultivated successful relationships with a number of Cummins’ largest customers. Jhawar has extensive global experience, with roles based in the Middle East, India, Europe and the US.

Jamestown Engine Plant commits to reducing water waste through reverse osmosis

JEP Reverse Osmosis

The Cummins Inc. Jamestown Engine Plant (JEP) is not only setting the standard for manufacturing top of the line engines. It’s also setting the standard for plants across the country as it makes progress on Cummins’ goal of having a net positive impact on local communities.

Part of Cummins’ Planet 2050 environmental sustainability strategy and 2030 goals aim to reduce absolute water consumption in facilities and operations by 30%. Plants like Cummins Mid-Range Engine Plant (CEP) in Columbus, Indiana have removed their 6.7 turbo diesel engine coating process to help reduce their water consumption. For JEP sustainability leaders, however, they hope to achieve this goal by eliminate 100% of potable water for irrigation, reusing 100% of fire test water and reuse 100% of treated wastewater. Recycling and reusing wastewater through the science of reverse osmosis (RO) will be one of the largest initiatives in plant history.

What is reverse osmosis?

Reverse osmosis is a technology that separates pure water from the outgoing waste streams by removing contaminants. This process is a major water-saver at JEP. 
In 2022, the plant used 16M gallons of fresh water, a 59% reduction in total water usages since 2016. Of that 16M, approximately 8M gallons leaves as wastewater to the local sewer system for treatment. The RO system provides the potential to recycle or reuse 80% of that outgoing water, which goes a long way towards meeting Cummins’ 2030 water reduction goals.

“If we want 30% - 50% water reduction at the plant, the reverse osmosis is what gets us there,” says JEP Machine Director Dave Burlee.
This is no easy feat, as a significant amount of effort is required to maintain an RO system at its peak efficiency. Water is extracted and reused in the deionizer (DI) water process which removes the metals, calcium and magnesium that are normally in city water.

“City water has a lot of minerals that we need to take out. The beauty of the RO system is that it removes 98% of it,” Burlee says. “We don’t want minerals in our water because when it evaporates, it leaves behind all that as scale – and we don’t want that in our cooling systems.”

How was wastewater regenerated before reverse osmosis?

Before the introduction of RO, wastewater needed to be regenerated — a process that creates giant vats of hazardous acid and caustic waste that requires treatment — every three or four days. Now, the water is fed into the DI where it can run for weeks before it needs to be regenerated, reducing the consumption of the acids and caustics associated with regeneration.

Today, 80% of deionized water used in the factory process is from the RO system.
“Our plant is a case study to show that it is viable to implement green energy solutions or energy conservation measures in a workplace such as ours with heavy machine manufacturing,” says Burlee.

Beyond just being viable, Burlee points out that the more significant impact comes with long-term viability. With machinery purchases, the return on investment (ROI) is usually one to two years. The ROI for green energy solutions, however, is usually closer to eight to 10 years. 

“You’re in it for the long haul. You’ve got to play the long game,” Burlee says. “The technology fits our manufacturing profile. So as long as up-front financials can be overcome, a business can see the long-term benefits of these things.”

The goal is a net positive impact in every community Cummins operates so that the sum of the environmental good is larger than the local environmental footprint. As the JEP plant continues to innovate, grow and invest, Burlee notes that, “Net Zero – it’s not just what our product does or how we assemble it, it’s how much it burns in its life cycle. How much energy did it take to mine all the raw materials to get there? It’s a whole circular life cycle mindset.”

5 reasons why you should take this quiz on next-generation alternative fuels

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Get ready to explore the world of alternative fuels and renewable resources with Cummins Inc’s "What fuels you - What next-generation fuel are you?" quiz. This quiz provides a fun and interactive way to understand how fuels have personalities just like us. It will help answer important questions like ‘What is the future of fuels for cars?’ and ‘How can we reduce our carbon footprint?’

By taking this quiz, you can discover which next-generation fuel matches your personality, whether you are renewable diesel, natural gas, or renewable electricity. Not only will you gain insight into the future of fuels and their environmental benefits, but you'll also exercise your brain and get a mood boost from taking the quiz.

Here are five reasons why you should take this quiz today:

1. It's quick and easy

The quiz only takes a few minutes to complete, so you can fit it into your busy schedule. Plus, you'll learn new information about alternative fuels and their many benefits.

2. It empowers you with knowledge about the future of fuels and energy

By taking this quiz, you'll learn about the latest innovations in the field of alternative fuels and renewable energy. You'll discover what Power-to-X fuels are, how renewable diesel works, and how hydrogen electricity compares to your personality. This knowledge can help you make more informed decisions about the fuels you use.

3. It provides brain exercise

Taking a quiz is a great way to exercise your brain and improve your decision-making skills. By challenging yourself to answer questions about alternative fuels, you'll be sharpening your mind and enhancing your cognitive abilities.

4. It's a mood booster

Taking a quiz can reduce stress and make you feel happy. This fun quiz will put a smile on your face and help you feel positive about the great work being done to make the world a cleaner place.

5. It helps you make friends

Sharing your quiz results with friends and colleagues can strengthen social interactions and allow you to connect with others who share your interest in alternative fuels and renewable resources. You never know, you might even meet a renewable diesel enthusiast who lives near you!

So, what are you waiting for? Take a break from your day and indulge in some self-discovery with this fun quiz about alternative fuels and renewable resources. Fuel your curiosity and gain valuable insights into the future of energy and fuels. Plus, you might just make some new friends along the way. Don't forget, we are on a path to a more sustainable future, and alternative fuels are a significant step in that direction.


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Cummins Office Building

Cummins Inc.

Cummins, a global power technology leader, is a corporation of complementary business segments that design, manufacture, distribute and service a broad portfolio of power solutions. The company’s products range from internal combustion, electric and hybrid integrated power solutions and components including filtration, aftertreatment, turbochargers, fuel systems, controls systems, air handling systems, automated transmissions, electric power generation systems, microgrid controls, batteries, electrolyzers and fuel cell products.

Driving toward a more sustainable future in the United States

Driving toward a sustainable future

The future of our planet depends on a decarbonized economy. At Cummins Inc., we believe the path to zero emissions involves both developing advanced internal combustion engines which can be deployed today, and innovating zero-emission solutions in markets where the infrastructure is ready. Cummins estimates that advancing both ways will contribute to 1.4 gigatons of cumulative carbon reduction. That’s the equivalent of removing all trucks from the road for three years.

So, what will the decarbonization journey look like for the transportation industry in the United States?

Diesel engines are becoming cleaner to meet emissions regulations

The transportation sector is responsible for roughly 27% of United States greenhouse gas (GHG) emissions. As one of the largest contributors causing climate change, transportation is in critical need of clean energy sources. Not all applications are ready for advanced technologies and will continue to rely on traditional energy sources for more years. Barriers to switching technologies include cost, infrastructure availability, reliability and technology readiness.

The good news is that diesel engines are becoming increasingly cleaner. Cummins is leading the way by investing more in diesel engine research and development than at any other point in its 100-plus-year history. Although improving fuel economy might not grab the headlines, it adds up to real results.

The trucking industry is also working to make sure engines can run on cleaner fuels, like biodiesel. Biodiesel B20 is a blend of 20% biodiesel and 80% petroleum diesel. B20 is a popular choice due to its numerous benefits, including lower emissions, cost savings from the Energy Policy Act fuel credits and good performance in cold weather. B20 also has the added benefits of material compatibility, and the ability to act as a solvent. There are already established quality standards and it can be used in current engines without modifications. It offers similar fuel consumption, horsepower and torque as petroleum diesel.

Natural gas engines are an alternative technology available now

In the on-highway market, light, medium and heavy-duty trucks need advanced technologies that are fuel efficient and get the job done. So, besides diesel, what are the other technologies available now for customers?

Natural gas engines are the mature, proven and least disruptive alternative power technology available today. These engines can use compressed natural gas (CNG), reducing GHG emissions by 13% - 18%. They can also run on renewable natural gas (RNG), a carbon-neutral fuel in most cases and carbon-negative in others, or a blend of the two.  Natural gas engines are a good fit for vocational trucks, transit and school buses, medium-duty and regional-haul trucks that have access to refueling infrastructure.

The joint venture between Rush Enterprises and Cummins seeks to enhance the production of near-zero emissions natural gas powertrains. This joint venture combines the strengths of Momentum Fuel Technologies’ compressed natural gas (CNG) fuel delivery systems and Cummins’ powertrain expertise. Fleets will be able to access both support networks, which represent over 250 locations in the U.S. and Canada. These locations are well-equipped with certified technicians and access to a natural gas vehicle parts inventory.

Powering tomorrow’s applications with batteries and hydrogen to reach net-zero emissions

Currently, battery-powered vehicles are limited by their range and payload capacity. That’s why they are less suitable for long-distance and heavy hauling applications. This is mainly due to the high cost and weight that large batteries require. The 2022 State of Sustainable Fleets report suggests that fleets with daily return-to-base routes under 200 miles and predictable access to charging stations will find it easier to adopt battery electric vehicles. Such applications are typically found in school and transit buses, and delivery and light-duty trucks, as well as regional goods trucks.

One way of solving the weight and cost issues mentioned above is by using hybrid systems. Hybrid systems incorporate both a combustion engine and a battery electric system. This can lead to increased fuel efficiency and reduced battery and engine size. It also eliminates the need for a large, costly battery. Creating demand for batteries in the commercial vehicle market will help manufacturing costs come down by creating greater economies of scale.

Beyond batteries, one of the most promising power technologies is hydrogen. As regulations limit greenhouse gas emissions from motor vehicles, both hydrogen internal combustion engines (ICE) and fuel cells are gaining interest. Hydrogen internal combustion engines are especially efficient for heavy trucks that operate under high loads. This technology can help fleets adapt to a new fueling infrastructure before fuel cells become more widely available, as they are still an emerging technology. Switching to hydrogen engines involves a familiar technology and engine architecture, while still advancing the hydrogen infrastructure. Both hydrogen ICE and fuel cells offer complementary use cases and have similar emissions profiles. They are two key components in reducing vehicle and transportation emissions and reaching net-zero missions.

Clean energy investments, such as the 2022 Inflation Reduction Act, are essential for driving the advancement of sustainable technologies and the necessary infrastructure. By investing in cleaner technologies, such as battery-electric or hydrogen, the United States can make significant progress toward combatting climate change.

Traci Kraus headshot

Traci Kraus

Traci Kraus is a Director of Government Relations where she leads US federal advocacy for Cummins. She focuses on energy, climate, hydrogen, transportation and budget legislative and regulatory issues. 

Prior to joining Cummins, Traci worked for former U.S. Senator Russ Feingold.  She has a Master’s in Public Administration from the George Washington University and B.A.s in Government and Politics and Communication from the University of Maryland in College Park. She is originally from Chicago, and now lives outside of Washington, D.C. with her husband, Aaron and two children Liam (8) and Sloane (5).

3 innovations that have shaped the advanced diesel engines of today

3 Innovations of Diesel

Today’s modern diesel engine is an impressive feat of innovation. Cummins Inc. is no stranger to innovation. In fact, the company spends $1 billion annually on research and technology across its product portfolio with 11,000 of the brightest engineers innovating for their customers. Today the company is taking a look at three of the innovations that have shaped the advanced diesel engines that are relied upon by so many different industries.

1. Digital Tools

The advent of the computer age revolutionized many industries and had an incredible impact on diesel engines. Integrating computer components into diesel engines improved the efficiency and overall performance. The computer in your diesel engine integrates with the ignition system, fuel injection process, emission system, transmission, exhaust system and more. Beyond these basic integrations, computer technology has optimized the advanced diesel engines of today with additional digital hardware, applications and capabilities, mobile applications, and digital hardware. Cummins offers a full suite of digital products and capabilities* that enhance the entire life of your Cummins engine. These include: 

Remote Engine Monitoring

Cummins now offers PrevenTech®, its newest remote engine monitoring and advanced analytics tool. PrevenTech® helps enhance operational efficiency for applications including trucking, mining, marine, and rail by using connectivity and data to monitor equipment health remotely and connect our customers to the industry’s largest service network. 

Predictive Service

Cummins now offers industry-first Predictive Service Insights, which alert truck fleets and service locations when specific components are likely to fail – providing a service recommendation allowing them to plan a replacement before an actual failure occurs. This technology is powered by data directly from the engine – helping customers avoid unplanned and costly downtime. These insights are available via PrevenTech® and can be found in Cummins’ genuine services tools including Guidanz®, INLINE™, and Quickserve Online.

Over-the-Air Capabilities

In the past, if you wanted to update the ECM (engine control module) software or engine parameters on a vehicle, you had to bring it to a service center or in-house repair location. Now, you can complete both of these service tasks over the air with Cummins’ application OptiTech®. OptiTech® allows you to update ECM software and a program a range of engine parameters from anywhere, using over-the-air technology. Allowing customers to adjust for changing terrain, duty cycles or driving preferences.

New Engine Technology

In February of 2020, Cummins announced its first connectivity-enabled X15 Efficiency series engine and new Endurant™ HD powertrain for Freightliner Trucks. This innovative technology included Cummins’ advanced engine computing module, known as Acumen®. This connects to Cummins’ technology platform for direct access to digital apps, over the air product enhancements, and future service integrations; able to securely communicate information through cellular connectivity, engines with Acumen® provide a deeper understanding of how vehicles operate in different environments and varying duty cycles. The new insights will be used to enhance machine learning and deliver more customized products and services.

*Your engine may not be eligible for all of Cummins’ digital products and capabilities. Please check with a Cummins representative, your original equipment manufacturer, or telematics service provider.

2. Emissions Reduction

Today's clean diesel engines emit 90% less harmful emissions that the engines produced before the year 2000. The aim of reducing emissions has led to increased efficiencies without sacrificing performance. Advancements in technology and clean diesel technology have helped diesel engines continue to improve. Important emissions reduction innovations by Cummins include: 

Optimized Powertrain Functionality 

Technology has played a vital role in helping reduce emissions. The new smart powertrains with Acumen® and Endurant™ HD improve fuel economy and significantly reduce emissions. For example, predictive gear shifting uses a combination of cameras, sensors, and traffic data to proactively upshift or downshift a vehicle based on upcoming road conditions. It allows the gears to change automatically, improving fuel efficiency and reducing mechanical straining on the transmission and associated parts. Other unique Cummins powertrain features include On-Ramp Boost, dynamic power, and hill roll-out.

Aftertreatment Systems

Emissions standards continue to evolve, meaning commercial vehicles with old diesel engine specifications aren’t up to the current standard. That’s why Cummins offers a wide range of aftertreatment technologies to meet these constantly evolving regulations. These aftertreatment systems contain Cummins Particulate Filter, which collects and oxidizes carbon to remove particulate matter by more than 90%. Once the particulate matter is removed, there is still nitric oxide and nitrogen dioxide left in the exhaust. In order to reduce these levels, an injection process introduces urea to convert these toxic emissions into harmless nitrogen gas and water vapor. This effectively eliminates harmful emissions resulting in reduced emissions from the exhaust.

Fuel-agnostic Engines

Derived from the diesel engine working principle, Cummins fuel-agnostic engine platforms are intentionally designed with commonality in mind. The series of engine versions come from a common base engine, sharing many of the same parts and components below the head gasket. Above the head gasket, there are different components for different fuel sources, allowing customers to choose from diesel, natural gas, and hydrogen to customize their transitions to zero emissions. Built on a legacy of innovation and dependability, Cummins leveraged research and insights from the millions of diesel and natural gas engines they have manufactured to design these reliable, fuel-agnostic platforms. This is an industry first, and this technology approach will be applied across Cummins’ product portfolio.

Cummins: Envisioning the Future of Diesel Engines in the U.S. and Beyond

Always innovating. That’s not just a slogan for Cummins, it’s their default setting. The company knows the future pulls us forward, and in order to keep up, Cummins must constantly meet that challenge. However good Cummins is today, they know the best is yet to come. The innovations listed above are just the beginning for the company, and they’re excited to continually reinvent the future of advanced diesel engines. Learn more about Cummins and their vision for the future

Cummins Office Building

Cummins Inc.

Cummins, a global power technology leader, is a corporation of complementary business segments that design, manufacture, distribute and service a broad portfolio of power solutions. The company’s products range from internal combustion, electric and hybrid integrated power solutions and components including filtration, aftertreatment, turbochargers, fuel systems, controls systems, air handling systems, automated transmissions, electric power generation systems, microgrid controls, batteries, electrolyzers and fuel cell products.

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