Natural gas engine insights for truck and bus fleets
There are growing choices in the commercial vehicle space that can help fleets reduce their overall transportation emissions. It can be a difficult space to navigate, whether a fleet is trying to keep up with tighter emission regulations or meet corporate ESG and sustainability goals. The complexities around incorporating lower carbon fuel types, training drivers, learning new service requirements, or cutting through the political uncertainty of alternative fuel adoption can be overwhelming and confusing.
Most importantly, though, fleets can’t afford major disruptions to their business model. They need to maintain similar performance and range they get from diesel engines to effectively run their business, while taking steps to run cleaner and more efficiently. That’s where Cummins can help.
Cummins is developing a wide range of low carbon solutions to help fleets begin the journey to zero emissions without causing major disruption to the day-to-day operation of the business. Cummins has products that deliver zero tailpipe emissions, like battery electric (BEV) and hydrogen fuel cells. We also produce near-zero internal combustion offerings, such as propane, hydrogen, and natural gas.
This article specifically focuses on compressed natural gas (CNG) engines and vehicles, known for their maturity, proven track record, and minimal disruption as low carbon vehicle options.
What are the benefits of natural gas engines and vehicles?
Natural gas engines and vehicles (or NGVs) have been around for decades. Cummins has a history of manufacturing CNG engines that dates back more than 30 years. We’ve built more than 85,000 natural gas engines in that time. The engines are tested, proven and available today.
Natural gas is an abundant domestic fuel source that isn’t connected to the global oil market. That means fuel is widely available and the price is more stable—and cheaper—than the price of diesel and gasoline.
Natural gas provides comparable power and torque ratings to diesel, making it seamless to integrate CNG vehicles into a fleet or replace older diesel trucks without sacrificing payload capacity or driving range. This is especially important for applications like transit bus, regional haul, garbage collection, and pick-up and delivery applications. A CNG vehicle is expected to go hundreds of miles and operate with a full load for most of the time it’s running.
Another major benefit of natural gas in transportation is the ability to achieve sub-zero carbon emissions with renewable natural gas (RNG). Renewable natural gas is manufactured primarily using methane that comes from the decomposition of organic waste. This includes landfill gas or methane captured from wastewater treatment facilities or agricultural waste.
Using RNG brings the total carbon intensity score down, because RNG is made with methane that would have otherwise been off gassed. Capturing these gases prevents their release, reducing well-to-wheel scores of RNG vehicles and dropping carbon intensity below zero, depending on the RNG feedstock. Renewable natural gas is also functionally identical to natural gas obtained from fossil resources. Blending fossil natural gas with even small quantities of RNG can result in immediate environmental benefits. And every year, RNG becomes a bigger percentage of all CNG being used in North America, contributing towards the role natural gas will play in our renewable future.
This major drop in the carbon intensity of RNG is one of the reasons why companies like Waste Management, UPS and Werner Trucking are making investments in natural gas trucks.
These companies aren’t alone. The 2022 State of Sustainable Fleets Report found that fleets with trucks powered by RNG consistently cite reduced emissions as a key benefit of natural gas vehicles. In 2021, the average carbon intensity of reported natural gas under California's LCFS was below zero, making NGVs the sole carbon-negative option for fleets.
What is the economic impact of switching to natural gas engines?
Throughout 2021, compressed natural gas maintained a clear cost advantage and relative price stability compared to diesel, which had a more volatile year. The clean fuel continued to prove its value, with the price of CNG increasing approximately 3% on average at public fueling stations compared to 2020.
Diesel prices increased nearly 19% nationwide and were, on average, 25% higher than the price of CNG on a DGE (Diesel Gallon Equivalent) basis. Fuel cost is a primary benefit of CNG users in the annual State of Sustainable Fleets survey, with 79% of respondents reporting lower costs as an advantage.
What applications are a good fit for natural gas engines?
Most commercial applications are a good fit for natural gas. There are many examples of natural gas engines on trucks and buses. Fleets leading the way in adopting NGVs include vehicles covering refuse, regional haul, transit bus, cargo, municipal and public utility applications. Just like diesel vehicles, these fleets “return-to-base” each day to refuel at CNG refueling points installed on-site for easier fill-ups.
For heavy, or long-haul trucks, refueling is more difficult. Long-haul trucks rely on public refueling stations along major interstates. Currently, the number of public CNG pumps is dwarfed by the number of diesel pumps, but Cummins and several transportation industry partners are making strides to change that. The company recently announced a plan to collaborate with Love’s Travel Stops and Trillium to enhance low and zero carbon fuel and powertrain solutions.
Cummins also recently announced plans to develop a 15-liter natural gas engine, the X15N, designed for class 8 long-haul applications. News of the X15N is already generating significant interest and excitement in the North American heavy-duty truck market. So much so it was named one of the Top 20 New Products of 2022 by Heavy Duty Trucking (HDT).
When does it make sense to transition to natural gas engines?
The bottom line is that when to switch to natural gas engines comes down to a business decision based on the specific duty-cycle and mission profile of an individual fleet. The operational and financial implications should be carefully evaluated. A growing number of businesses recognize the benefits NGVs provide, but each situation is different.
Never miss the latest and stay ahead. Sign up below to receive the latest in technologies, products, industry news, and more.