Introduction into Renewable Natural Gas (RNG)
What is RNG?
Renewable natural gas (RNG) is a sustainable fuel created by capturing methane from decomposing organic waste. Unlike fossil fuels, RNG is produced from materials such as animal manure, food scraps, used cooking oil, wastewater sludge, and other biodegradable waste.
These materials naturally release methane as they break down. Instead of letting that methane escape into the atmosphere—where it’s over 25 times more potent than carbon dioxide (CO₂) as a greenhouse gas—RNG production captures and purifies it into a usable fuel. This process not only provides an alternative energy source but also helps reduce emissions from landfills and other waste sources.
What’s the carbon intensity of RNG?
The carbon intensity (CI) value of RNG depends on the feedstock used to produce it. Dairy manure and agricultural waste typically result in ultra-low or even carbon-negative CI scores. RNG from food waste or landfills still offers a much lower CI than diesel but generally remains carbon-positive. Even so, all forms of RNG help reduce lifecycle emissions compared to traditional fossil fuels.
How can you get RNG?
Renewable natural gas and compressed natural gas are interchangeable and can be blended together. Most fleets get RNG through their fuel provider or utility company. Businesses wanting to switch their vehicles to RNG can either build a fueling station on-site or use existing public refueling stations. Fleets with an existing fuel or lube contract can start by asking their current supplier about the exact source of their natural gas or connecting with Cummins for more information.
Benefits of RNG-powered trucks for your business
RNG Trucks: Myths vs. Facts
FACT: That’s a myth. For example, the Cummins X15N™ natural gas engine delivers up to 500 hp and 1850 lb-ft of torque — plenty of power for heavy loads and long routes. It’s built specifically for Class 8 trucks and has already undergone testing with fleets like Walmart, UPS, J.B. Hunt, Werner Enterprises, and others.
FACT: Natural gas engines and vehicles have been around for over 30 years. They are the most mature, proven and least disruptive low-carbon vehicle available today and offer a true 1-1 vehicle replacement for diesel.
FACT: While heavy-duty natural gas trucks have a higher upfront cost than diesel, they are more cost-effective than zero-emission options like battery electric or hydrogen fuel cell. Fleets can recoup some upfront costs through fuel price savings, since natural gas is less expensive than diesel. The more miles the trucks accumulate, the faster the upfront costs are recovered. Fuel providers and Cummins offer Total Cost of Ownership calculators and can help you and your preferred carrier identify potential routes to be converted so you can look at scenarios that make sense for your business and operating model.
FACT: The trucking industry leverages the existing natural gas pipeline and fueling infrastructure, with over 3 million miles of distribution lines and a mix of more than 1,500 public and private fueling stations across the United States. Fleets can also install on-site fueling where it makes sense. As RNG production expands, availability continues to grow—making it a practical, scalable solution today. Fuel providers can help assess availability in your area or explore options for on-site infrastructure if it fits your business model.
FACT: Not more — just different. Natural gas engines avoid complex diesel aftertreatment systems, making upkeep simpler. But it’s critical to follow recommended maintenance intervals — especially for things like oil and spark plug changes — to keep them running reliably.