Diesel vs. Gas Generator Sets

Electric Diesel Generator: Everything You Should Know

Diesel generators are rising in popularity. With cleaner fuel, better efficiency, and fewer maintenance requirements compared to conventional generators.

This guide provides a comparative analysis of fuel efficiency and cost of diesel vs. gas generator sets, along with other aspects like noise levels, performance, and average generator set sizes. 

Diesel vs. Gas Generator Sets: An In-Depth Comparison

The detailed comparison in this guide will include the following comparison points:

  1. Fuel type
  2. Performance
  3. Noise levels
  4. Maintenance
  5. Generator set size
  6. Safety considerations
  7. Environmental impact
  8. Price

Let’s break down every point.

Fuel Type

The primary difference between diesel and gas generator sets is the fuel they utilize. While diesel generator sets run strictly on diesel fuel, gas generator sets may operate on gasoline, natural gas, or propane in some cases. 

The fuel type difference is why diesel generator sets are more efficient compared to gas generator sets.

Diesel fuel has a higher density than other fuel types, allowing for the diesel generator to produce more electricity from the same amount of fuel compared to a gas generator. 

Further, diesel is widely available and has a longer shelf life compared to gasoline or natural gas.

However, diesel is often more expensive than gasoline and natural gas. Gas is also more readily available than diesel, and often easier to access. 


Diesel engines in generator sets tend to last longer and require less maintenance than gas engines. Diesel generators also have lower emissions, offer better cold weather starting, and provide steadier power output compared to gas.

Diesel generators have higher running wattages for the same engine size compared to gas. For example, a typical 5 kW diesel generator may have a 389 cc engine, while a 5 kW gas generator requires a 993 cc engine to produce the same power.

As such, diesel generators can be a better choice when reliable performance is required. Hospitals, industrial sectors, remote locations, and construction sites often go for diesel generators for their better performance.

Noise Levels

Both diesel and gas generator sets have various noise levels depending on their power, RPM, and load. As such, it’s difficult to claim that one of them is louder or quieter than others.

However, both diesel and gas generator sets can be containerized for better acoustic control, reducing noise levels to as low as 70 dB. 


Diesel fuel is less flammable and not as hard on engine components compared to regular gasoline. As such tune-ups are considerably less in diesel generator sets, reducing their overall maintenance requirements.

However, for that to happen, diesel generator sets require more extensive fuel filtration and water separation systems. Further, diesel fuel is a bit more susceptible in cold weather to bacterial growth compared to gasoline.

Still, during long-term use, diesel generator sets’ increased durability and lower maintenance costs can save you a decent amount of cash in the long run, especially if your establishment requires multiple generator sets. 

Generator Size

Diesel generator sets have more efficient engines that can produce more power in smaller sizes. As such, it can be advantageous to get a diesel generator set if you have limited space.

However, both types of generator sets can be manufactured at any size. 

Safety Considerations

Diesel and gasoline both have flammability risks that require safe handling and storage. However, diesel’s higher flashpoint means it is less of a fire or explosion risk than gasoline.

In other words, diesel generator sets can be considered safer than their gasoline counterparts. 

Still, proper ventilation, fuel management, spill containment, and following local electrical codes are important safety steps for any generator set. 

Environmental Impact

Compared to a gasoline generator set, a diesel generator set produces lower emissions of hydrocarbons and carbon monoxide when run for the same duration.

However, some gasoline generator sets with catalytic converters or other emissions controls can minimize pollution output. Still, such gas generator sets are more expensive than regular generators.


It’s hard to determine the exact prices of diesel or gas generator sets, as the price range differs with the specs. However, on comparing a diesel generator set and a gas generator set with similar performance, you’ll find that diesel generator sets may have a higher upfront cost. 

Diesel vs Gas Generator Sets: Pros and Cons

To summarize the whole comparison, here are the pros and cons of both generator set types:

Electric Diesel Generators


  • Highly efficient when it comes to fuel consumption.
  • Better performance compared to gas generator sets.
  • Considerably quieter than gas generator sets. 
  • They are easier to maintain in the long run.
  • They are safer to use. 
  • They have less environmental impact.


  • They may have a high upfront cost.
  • The diesel fuel may be less accessible than gasoline. 

Electric Gas Generator Sets


  • They may be cheaper than diesel generators.
  • Their fuel is more readily available.


  • They can be louder than diesel generator sets when operating at full power.
  • Efficiency and performance are inferior compared to diesel generator sets.
  • They produce more emissions and leave a bigger environmental impact. 
  • They can be costly to fuel and maintain in the long run in some regions. 


What are the Disadvantages of Diesel Generator Sets?

The primary disadvantage of diesel generator sets is their initial price, which can be higher than gas generators of the same specs.

Some people argue that their size makes them difficult to transport, but newer designs are eliminating this obstacle. Lastly, for them to require less maintenance, their fuel needs to be well-filtrated. 

What are the Disadvantages of Gas Generator Sets?

A gas generator set’s primary disadvantage is its high fuel consumption and its higher emissions. It’s also not as strong as a diesel generator set of the same class.

Do Diesel Generator Sets Run Longer Than Gas?

Yes, diesel generator sets can run longer than gas generator sets using the same amount of fuel. That’s because diesel is more dense than gasoline, allowing it to produce more energy with the same amount. 

Which Is Better, a Diesel or Petrol Generator Set?

Despite its initial cost which could be somewhat higher, a diesel generator set has an edge when compared to a petrol generator set. Unless you need a cheap generator set for occasional use, diesel generator sets are more reliable, efficient, quiet, and easy to maintain. 

Final Thoughts

In summary, diesel generator sets are generally the superior choice over gasoline generator sets for most applications due to their higher efficiency, durability, and reliability.

However, for some temporary or intermittent uses, a gasoline generator can still be a viable option if fuel, noise, and emissions are not major concerns.

If you need a premium diesel generator set, we invite you to check our product list on Precision Industries’ official website. If you have any questions, don’t hesitate to reach out to us. We’ll get back to you as soon as possible.