What Is the Difference Between a Natural Gas Generator and a Diesel Generator?

natural gas generator vs diesel generator

If you’re considering a natural gas or diesel generator, several factors come into play, like unit costs, emissions, applications and, of course, fuel sources. Both have unique benefits, so examining key aspects of each will help determine which type of generator best aligns with your operations.

When it comes to diesel vs. gas generators, the old-school way of thinking was that diesel engines were loud and disruptive and gas units were expensive and temperamental. But now, both versions are reliable power generation solutions that can support various applications and industries across the board.

Continue reading for more about the differences between gas generators and diesel generators.

What Is a Natural Gas Generator vs. a Diesel Generator?

The main difference between a gas generator and a diesel generator is the type of fuel source, but how they produce energy is also different. A natural gas generator uses spark plugs to ignite the fuel and air mixture, while a diesel generator compresses air into a cylinder to generate heat. Ignition occurs when a small amount of diesel fuel is introduced.

Both types of generator options deliver incredible power solutions, whether you’re searching for a prime, standby or portable power source. Each generator can support a multitude of applications with unique advantages to each, such as providing power to hospitals, construction sites, neighborhoods, schools, homes, data centers and more.

Advantages and Disadvantages of Natural Gas Power Generation

The terms “gas” and “natural gas” are often used interchangeably. However, they’re sourced differently. Additionally, a gasoline generator mixes fuel and air inside a chamber prior to combustion, while a natural gas generator uses spark plugs to ignite the mixture. Consider these differences when researching generator types.


Several pros of investing in a natural gas generator include:

  • More readily available fuel source connected to gas lines
  • Costs less to purchase a unit and the fuel
  • Cleaner emissions compared to fossil fuels like coal and oil
  • No strong odors emitted

natural gas generator is ideal for prime power applications because it’s usually linked to a consistent fuel source. For example, natural gas pipelines often exist throughout the grid of a metropolitan area, making it a more reliable source of fuel. These units are also more affordable and produce cleaner emissions in comparison to diesel and other fossil fuels.


 However, some cons when it comes to a natural gas-powered generation system include:

  • Requires more maintenance
  • Shorter lifespan
  • More explosive fuel
  • Emits more carbon dioxide compared to a diesel generator
  • Natural disasters can affect gas supplies

Investing in a natural gas generator may be less expensive initially, but sometimes they require more maintenance, resulting in higher repair costs, more downtime and a shorter lifespan. Further, natural gas is more prone to fire hazards, so you’ll need to prepare with additional safety precautions when working with natural gas solutions. Finally, natural gas can be a disadvantage during natural disasters. In cases where the lines become destroyed, shut off or broken, you may lose power.

Advantages and Disadvantages of Diesel Generators

A diesel generator compresses air inside the cylinder until it begins to build heat on its own. Then, a small amount of diesel enters the cylinder separately, causing ignition. This process allows the diesel engine to run more efficiently while using less fuel.


A few advantages of diesel generators include:

  • Require less maintenance
  • Reliable and longer lifespan
  • Higher fuel efficiency levels
  • Less flammable and explosive

Compared to natural gas generators that are more cost-effective but require extra maintenance, diesel units have a higher upfront cost yet demand less upkeep throughout the year, lowering your power system maintenance costs. This also results in a more reliable, heavy-duty generator with a longer lifespan. These generators are ideal for off-grid applications that aren’t connected to a primary fuel source like natural gas.


In comparison, several disadvantages of working with diesel generators include:

  • Diesel fuel costs can fluctuate to higher prices
  • Tier four models are more expensive
  • Old versions emit louder sounds than natural gas generators, depending on the model
  • Not connected to pipelines, so fuel must be stored

Because diesel fuel isn’t readily available through the grid like natural gas, you must store or procure it long-term. Also, diesel fuel prices are typically higher than natural gas. While diesel generators are great standby and portable power sources, they’re often not the first choice when it comes to main power applications because it’s not as easily procured as natural gas.

However, while you often pay more for diesel fuel, the trade-off of higher efficiency rates balances it out. Diesel has a higher energy density, meaning it delivers more usable power compared to natural gas. If you invest in a tier four diesel generator, it’ll emit less nitrogen oxide and particulate matter compared to older generation models.

Diesel vs. Gas Generator Facts and Considerations

In summary, here’s what we know about diesel and natural gas power sources:

  • Diesel: These generators compress only the air, allowing the unit to use less fuel and operate more efficiently. As a result, diesel-powered generation systems run longer on the same amount of fuel as natural gas generators, providing uninterrupted power. With contemporary diesel models becoming more advanced, they now run more quietly, need less maintenance and require fewer replacements compared to natural gas generators.
  • Natural gas: When it comes to natural gas solutions, individual units are often more cost-effective and portable with cleaner emissions. One of the biggest benefits of natural gas is being connected to a consistent and reliable grid that costs less than diesel fuel prices. In contrast, you have to procure and store diesel that’s not as readily available.

Now that you have the facts, you’ll want to think about which type of generator best fits your applications. Consider the following:

  • Do you need a generator for main or emergency use?
  • How many appliances and projects do you need to power?
  • What’s your budget?
  • Will you have access to a consistent fuel source?
  • How much time, effort and money can you put into maintenance?
  • Does your business need to adhere to emission standards?

There’s no right or wrong answer when it comes to investing in a natural gas or diesel generator. It all comes down to your specific application, budget and access to either fuel source.

diesel generator vs natural gas generator

Mustang Cat® has a range of natural gas and diesel units available, whether you’re looking to purchase a new or used unit or need to rent one for a certain period. Mustang Cat delivers top-of-the-line products across the board while giving you access to parts and services for your diesel or gas generator.

Located in Southeast Texas, Mustang Cat has been family-owned since its inception in 1952. Our team has your best interests in mind when it comes to Cat equipment for purchase or rental. 

Reach out to our team of experts with industry-leading response times to learn more about our generator options or visit a Mustang Cat location near you.