Feeling the squeeze of the surging fuel costs? This is already forcing fleet managers to reevaluate their fuel choices. Because of new emissions rules, constrained budgets, and incentives on alternative fuels, choosing between propane vs. natural gas is now more critical than before. All these influence the way the fleet managers strategize their fleet fueling plans.
Looking closely at costs with a natural gas vs. propane cost calculator shows how each fuel compares. But price is only part of the picture. Infrastructure, performance on a daily basis, and emissions are other factors to be taken into account. To assist the fleets in selecting the correct fuel, this post describes the differences between propane and natural gas.
What Are Propane and Natural Gas?
Found underground, natural gas is a fossil fuel made mostly of methane and other small quantities of hydrocarbons and inert gases. It is extracted and processed for use. But a lot of individuals mix propane and natural gas.
So, one wonders, “Is propane natural gas?” Propane, sometimes known as Liquefied Petroleum Gas (LPG), is not immediately accessible from subterranean reserves. But rather, it’s a by-product of natural gas extraction and oil refinement. Here we’ve shared what is liquid propane vs. natural gas in detail:
Propane
Propane is extracted and purified during the natural gas processing and oil refining and is stored in the form of a liquid under moderate pressure. So, it’s easy to transport and refuel.
Its mobility also makes it ideal for light- and medium-duty trucks, including forklifts, heating, cooking, farm machinery, school buses, and delivery vans. Moreover, because of a large supply network and many refueling choices, the propane system is also simple and reliable.
Natural Gas
Natural gas is turned into Compressed Natural Gas (CNG) or Liquefied Natural Gas (LNG), which is used in vehicles. CNG is kept in high-pressure tanks and is well-fitted in local fleets. While LNG is refrigerated to a liquid that is used in heavy-duty trucks that have long ranges. Storage requires either high-pressure tanks for CNG or very cold, insulated tanks for LNG.
Comparing Fuel Cost and Availability for Fleets
The largest consideration to make when comparing propane and natural gas for a fleet is how much the fuel will cost in general. What type of infrastructure will you use it with? These decisions influence your budgets, operations that happen on a daily basis, and your long-term plans. Here’s how:
Fuel Prices and Market Volatility
The content of propane and natural gas does not match, and thus, comparing their prices using the cost per gallon is impossible. Propane is available by the gallon, and natural gas is available at an equivalent of gasoline and diesel gallons. Furthermore, propane is usually cheaper than gasoline or diesel, yet it has less energy, and therefore, vehicles consume more of it. Its price also changes a lot with oil markets and seasonal demand.
Natural gas has more stable pricing, and utilities can offer fleets long-term rates. CNG and LNG have the capability to compete with diesel prices based on energy equivalence. Nevertheless, the prices still do not remain the same across the regions since they are determined by the local pipelines and production plants. But regions with a good gas infrastructure tend to be less expensive.
Fueling Infrastructure and Availability
Natural gas and propane have very different fueling systems. Propane is widely available, even in rural areas. Refueling is easy and cheap, as well as on-site tanks and dispensers can be installed by fleets without any special training. The natural gas fueling system, in turn, is more complicated and expensive.
While CNG requires high-pressure compressors and a lot of electricity, and therefore, its public stations can only be found along major trucking routes. Whereas LNG requires super-cold storage and limited public stations. The two fuels also require qualified personnel to operate high-pressure or cryogenic equipment. On-site CNG stations can be installed for fleets, but fast-fill stations cost more, whereas overnight time-fills are less expensive for fleets that return to their base.
Vehicle Compatibility and Range
For fleets exploring alternative fuels, propane, CNG, and LNG each suit different needs based on vehicle type and daily driving range. Here’s how:
Vehicle Options for Propane
Propane vehicles are affordable and best for short, predictable routes. They are available as factory-made models or through conversions. Propane is popularly used with fleets on fixed daily routes such as school buses, shuttles, municipal vehicles, or delivery vans. The fleets may also opt to have special propane or bi-fuel vehicles, which can use both propane and gasoline to offer more flexibility and extended range.
Vehicle Options for Natural Gas
CNG is in a high-pressure state and is useful to vehicles that have regular daily routes and refuel overnight, like transit buses, garbage trucks, and local delivery fleets. While LNG is cooled into a liquid to achieve the highest energy density. It’s best in heavy-duty, long-range trucks that can afford a long delay between refuels.
Fuel Range Comparison
The range of fuels depends on their type, and impacts payload and infrastructure. Propane has a short range compared to diesel or gasoline. However, it is also refueled easily and cheaply. While CNG tanks are heavy and of high pressure, and this can reduce payload and raise costs. But some vehicles can travel up to 1,000 km (620 miles) per fill. Whereas LNG has the greatest range of about 1,500 km (930 miles). Hence, it is suitable for long-distance routes.
Emissions and Environmental Impact
Propane and natural gas are cleaner than diesel because they burn more efficiently and contain less carbon. Propane emits about 5.72 kg of CO₂ per gallon, compared with 10.21 kg for diesel. While natural gas has a slight carbon advantage over propane due to its simpler chemistry. However, a crucial difference is methane. Propane releases almost none. But natural gas can leak or emit unburned methane from engines, which can limit its climate benefits because methane is a very strong greenhouse gas.
There are trade-offs as well. Studies show that heavy-duty natural gas trucks can emit more ultrafine particles than modern diesel trucks with particulate filters. These particles mostly come from engine oil and can affect air quality in cities. Methane leaks during fuel production or use can also reduce natural gas’s overall emissions advantage.
But renewable fuels offer much bigger emissions benefits. Renewable propane, made from waste oils and fats, can have up to four times lower carbon intensity than regular propane. Whereas renewable natural gas (RNG) comes from landfills, farms, and wastewater plants. It can deliver net-negative emissions by capturing methane, while using existing natural gas and CNG infrastructure.
For fleets, propane and natural gas can help meet future emissions rules. The right choice depends on whether the priority is cutting greenhouse gases, improving local air quality, or controlling costs. Many fleets can begin with renewable fuel blends, which reduce emissions right away without engine changes. This will allow them to benefit from incentives as the renewable fuel supply expands.
Safety, Storage, and Maintenance Considerations
Selecting an alternative fuel calls for knowing the safety, storage, and maintenance demands of that particular fuel. Each of the named propane, CNG, and LNG has unique needs that affect management, refueling, and periodic maintenance. Here’s how:
- Propane: Beneath moderate pressure, this is maintained as a liquid. Though combustible, it weighs more than air and disperses readily in the open areas, hence lowering the danger of leakage. Compared to CNG, propane tanks are also lighter and smaller and may be easily substituted or replaced.
Propane also burns clean. Hence, engine oil and spark plugs have a long life. Maintenance mainly focuses on checking fuel lines and seals, and technicians need only standard training for pressurized systems.
- CNG: It’s stored at very high pressures, up to 3,600 psi, in heavy composite cylinders with a service life of 15–20 years. These tanks require regular visual and pressure inspections every 3–5 years.
Storage areas must also be well-ventilated since CNG is lighter than air and can accumulate indoors. CNG maintenance requires trained technicians, with a focus on fuel injector care, as the fuel doesn’t lubricate engine parts. Besides, modern CNG engines use hardened materials to prevent valve wear.
- LNG: It is kept at -162°C (-260°F), and requires delicate attention in order to avoid cryogenic burns and manage quick gas expansion. Workers need specialized PPE and cryogenic training.
Maintenance also focuses on the super-insulated fuel tank, monitoring evaporation (“boil-off”), and ascertaining that insulation and pressure relief systems function properly. Fuel system care is similar to CNG but includes extra steps for cryogenic components.
Which Fuel Is Better for Your Fleet?
The most premium fuel for a fleet is based on the type of vehicles, the number of miles per day, and the base operations. Here’s how:
Best Fit for Light- and Medium-Duty Fleets
For light- and moderate-duty fleets, propane is the preferred alternative. Good examples are school buses, shuttles, municipal cars, and local delivery trucks (Classes 2–6), which come back to a central depot.
Propane is also less expensive than gasoline or diesel, as it’s cheaper to maintain and simpler to refuel. It is used on predictable routes, those less than 400 km (250 miles) per day, where tank management is simple, and the network supply is extensive. Propane also aids in minimizing emissions without any impact on payload.
Best Fit for Heavy-Duty and Long-Haul
In the case of the Class 8 truck and transportation over distance, natural gas is an appropriate fuel. CNG is suitable for local fleets such as transit buses, refuse collection, and local freight that follow predictable routes, albeit with heavy tanks that slightly decrease the payload. Whereas LNG is superior for long-haul trucks that travel 800+ km (500+ miles) per day. It provides large energy density, diesel-like range, and low payload loss, also making it suitable for dedicated LNG corridors.
| Factor | Propane | Natural Gas (CNG / LNG) |
| Fuel Cost | Lower upfront infrastructure cost, fuel often cheaper than gasoline/diesel but has lower energy content, so usage may be higher, price affected by oil markets and seasonal demand. | Generally stable pricing, can be cost-competitive with diesel on a DGE basis, regional pipeline access affects cost. CNG is cheaper than LNG, long-term contracts help stabilize costs. |
| Refueling Infrastructure | Simple, low-cost, widely available, easy onsite tanks; refueling requires minimal specialized training. | CNG requires high-pressure compressors, LNG requires cryogenic storage, infrastructure is costly and complex, public stations mostly along major routes. |
| Vehicle Range | Shorter range compared to diesel/gasoline, suited for known routes under roughly 400 km (250 miles). | CNG: good for regional fleets, medium range, heavy tanks minimize payload. Best for long-haul, LNG has the longest range, up to around 1,500 km or 930 miles. |
| Emissions | Lower emissions than gasoline or diesel, clean-burning, and reduces engine wear. | Lower emissions than diesel, CNG and LNG both reduce greenhouse gases and pollutants. |
| Availibility | Very prevalent, even in rural areas, excellent supply network, and simple distribution. | CNG is more accessible in urban and regional centers, LNG is confined to certain specialized stations and trucking routes. |
Key Takeaways
When comparing propane vs. natural gas, they suit different fleet needs. Propane is simpler and less expensive to implement with light- and medium-duty fleets that have predictable and local routes. CNG and LNG, in their turn, are more suitable for heavier vehicles or for long-haul activities needing more power and greater range
Both propane and natural gas, however, reduce emissions when you compare them to diesel. Also, the fuel range of the vehicle, fueling facilities, daily operational demands, and cost must be taken into account while selecting the best fuel.
FAQs
1. Is propane cheaper than natural gas for fleets?
Which one is cheaper, propane or natural gas, depends on its cost and efficiency. Natural gas tends to have a lower price per unit, yet propane contains more power, and thus vehicles will require less of it.
In order to make the comparison, multiply the price per gallon of propane by 1.09 to obtain an equivalent of a therm of natural gas. Besides, CNG and propane can save 30-40% and 30-50% of fleets, respectively, over diesel. The two fuels also reduce long-term maintenance costs.
2. Can I convert my diesel trucks to propane or CNG?
Yes. Diesel trucks can be changed to propane or CNG, though the conversion varies depending on the fuel. Light-duty trucks cost $4,000-$12,000 for EPA-approved propane conversions and $12,000-$18,000 for CNG conversions. Whereas heavy-duty trucks can cost more than $20,000.
3. Which fuel is safer for fleet vehicles?
Both natural gas and propane are safe if properly managed. Since propane is heavier than air, if a leak happens, it would settle in low areas. Besides, its powerful smell makes it simple to recognize. It’s also stashed in durable tanks that are able to survive collisions. While natural gas still needs checking for high-pressure CNG and cryogenic LNG tanks, despite being lighter than air and ascending.
4. Is propane more widely available than CNG?
Propane is widely accessible through ~2,500 public stations and is easily delivered at the site, so it becomes available even in rural regions. While CNG has a smaller and more concentrated network on major trucking routes and cities. But it’s better suited for fleets with a fixed-route, central refueling station.
5. Does Fuel Logic deliver propane or CNG?
Yes. Fuel Logic offers on-site delivery of diesel, gasoline, DEF, or alternative fuels such as propane (autogas) and CNG for fleets.
Plan Your Fleet’s Fueling Strategy with us
Fuel Logic can help you plan your fueling strategy, including the kind of fuel and the mode of delivery that will suit your fleet. We offer on-site fueling so that your fleet is not held up. Moreover, we provide emergency and mobile fueling services anywhere in the country, including remote locations. You can make a fuel order, talk to our Fuel Logic expert for advice, or call us for more information!
