Diesel Vs Natural Gas Generators – [Who is The Winner?]

Diesel generators are known as workhorses because of their solid-built, powerful engines and higher efficiencies. On the other hand, natural gas machines are less expensive with modern designs and also emit very little noise and odor.

The bottom line is that both machines have pros and cons depending on the usage and requirements of the owner.

This guide will help you to choose between them!

Diesel Vs Natural Gas Generators

Diesel Vs Natural Gas Generators – Quick Comparison

ParametersDiesel GeneratorsNatural Gas Generators
Fuel TypeDieselNatural Gas
Power OutputHighLow
Initial InvestmentHighLow
Fuel CostHighLow
Maintenance CostLowHigh
Fuel EfficiencyHighLow
Fuel AvailabilityEasily availableEasily available
Safety FeaturesVery SafeNot Safe (Due to the high flammability and volatility)
Noise LevelsLoudQuiet
Performance in Cold WeatherChallengingQuick Start-Up
MaintenanceEasyRequires frequent inspection
EmissionsHigh Very Low

Detail Comparison of Diesel and Natural Gas Generators

Fuel Efficiency/Runtime:

Diesel generators are more efficient when compared to the same volume of gas needed for a Natural gas generator.

This is because diesel fuel has more energy density with negligible moisture and air content hence providing longer runtime compared to the same amount of natural gas.

As per our tests, diesel generators are 20 – 30% more efficient and provide uninterrupted runtime, as long as you have the fuel you can run the machine anywhere, that is the reason most industrial sites and hospitals have diesel machines.

WINNER: Diesel Generators

Power Output/Capacity:

Because of higher energy density, diesel generators provide more power output compared to natural gas. Also provide a super stable output which is why they are well-suited for applications requiring high power outputs.

WINNER: Diesel Generators

Initial Cost:

Diesel generators typically need more upfront cost because of their larger size and durable engines, however, the cost difference is mitigated over time as the diesel generator is more efficient with higher power and also needs lower maintenance costs compared to natural gas generators.

The installation cost is very similar between diesel and natural gas machines depending on the configuration, cabling distance, and local labor rates.

WINNER: Natural Gas Generators

Fuel Cost:

The cost of diesel and natural gas significantly varies over time, however as per the current rates diesel is 3 to 4 times more expensive compared to natural gas, also you need to prepay the bills during the refills, however, in the case of natural gas, you will have to pay 3 to 4 times less and also can be paid monthly.

WINNER: Natural Gas Generators

Maintenance and Repairing Cost:

Diesel Vs Natural Gas Generators maintenance

Diesel generators are built to withstand higher loads and extreme weather, hence they hardly need to be repaired, whereas natural gas machines need frequent repairs depending on the brand and how they are being maintained.

Also due to the absence of spark plugs and extremely sturdy built, diesel machines need lower maintenance costs.

WINNER: Diesel Generators


Diesel generators guarantee stable power with maximum power output, that’s why larger institutes, industries, hospitals, and ships use diesel gen sets.

As long as you have fuel you can run the machine anywhere, unless there is a mechanical or electrical fault.

However, In the case of natural gas, the supply may be interrupted during a disaster or major accident.

WINNER: Diesel Generators

Noise Levels:

Diesel generators are comparatively louder because of the crankshaft and piston that convert the liquid fuel to a fine combustible mist.

WINNER: Natural Gas Generators


Because of the robust and simpler mechanical design, diesel generators are rugged and can last twice as compared as natural gas machines.

Diesel engines are specifically designed to tolerate higher temperatures, and pressure so that they can be used for giant industries, hospitals, and ships as well.

WINNER: Diesel Generators

Safety Features:

Natural gas is highly volatile and flammable compared to diesel fuel, a minor leakage could be a reason for a huge destruction. Natural gas pipeline kits, joints, etc., need proper care and regular inspection.

Diesel fuel also needs proper care; still, it’s not volatile and flammable compared to other fuels. Also due to the absence of spark plugs the risk of freak fires is very low.

WINNER: Diesel Generators


For optimum performance and longevity, both natural and diesel generator needs periodic maintenance. However, for the sake of comparison diesel engines have relatively simpler mechanisms with no spark plug; also, diesel fuel doesn’t clog the engine hence they need less maintenance compared to a natural gas machine.

WINNER: Diesel Generators


Natural gas is more environmentally friendly as it emits 13 – 17% less Greenhouse gases (GHG) including NOx, SOx, etc., also 27% less CO2 compared to diesel engines. Moreover, it can be a renewable source of energy when it is made with biogas.

NOTE: Natural gas contains mainly CH4 (methane) a pure Greenhouse gas that can destroy the environment drastically, furthermore a small leakage could not only increase the bill but also hurt the environment.

Please make sure to inspect the pipelines, joints, and cylinders deeply so that there will not be a chance of leakage.

U.S. Environmental Protection Agency (EPA) has estimated that 33% of total U.S. methane emissions come from storage tanks, pipelines, processing plants, and natural gas wells (Source: U.S energy information Administration).

WINNER: Natural Gas Generators

Recommended Guide: Detailed Comparison of Diesel and Gasoline Generators

What Are the Advantages of Diesel-Powered Generators?

  • Provide more efficiency compared to the natural gas generators
  • Steady optimum outputs, that’s why data centers and hospitals mostly have diesel generators
  • Less maintenance and repair costs with greater longevity.
  • Cost-effective
  • Safer to use as diesel fuel is relatively less flammable and volatile compared to natural gas.
  • Ideal for mobile use.
  • Provide more power output because of the higher energy density.

What Are the Disadvantages of Diesel-Powered Generators?

  • Diesel generators are expensive compared to the natural gas machine.
  • Diesel gen-sets are louder because of the heavy mechanisms.
  • Emits more GHG (greenhouse gases) and other harmful pollutants.

What Are the Advantages of Natural Gas Generators?

  • Environmentally friendly with less emissions of GHG (Greenhouse gases) i.e. CO2, SOx, NOx, etc.
  • Unlike diesel generators, natural gas machines do not emit a pungent odor from the generator’s fumes.
  • Lower fuel cost.
  • Readily available in the countryside.

What Are the Disadvantages of Natural Gas Generators?

  • Less stable power compared to the diesel machine.
  • Not reliable, the gas supply can be interrupted due to a disaster or any accident.
  • Require more repair and maintenance costs.
  • Extremely explosive and need extra care for handling.
  • Shorter life.

Concluded Results: Diesel Generators are the Winners

Frequently Asked Questions – FAQs

Is It Cheaper to Run a Generator on Natural Gas?

Yes, natural gas is 3 to 4 times cheaper compared to diesel.

Are Natural Gas Generators Quieter Than Diesel?

Yes, due to the super silent running mechanism natural gas gen-sets provide super silent operation, my Generac Guardian 24KW is emitting around 60 to 65 dB (A) from 5 – 6 feet at the load of 50 – 60%. However, a normal diesel generator from the same distance and load surely emits 70 – 75 dB (A).

Can I Power My House With a Diesel Generator?

Yes, diesel generators are built to run huge houses, industries, institutes, hospitals, or even ships.

What Is the Life Expectancy of a Diesel Generator?

It depends on the quality of the machine and how well it’s maintained, as a general thumb rule a solid branded standby diesel generator can last for about 10,000 to 30,000 running hours (about 25 – 40 years).

What Is the Life Expectancy of a Natural Gas Generator?

It depends on the quality, brand, and how the machine is being maintained, as per the general thumb rule a branded natural gas generator from a well-known manufacturer can last for about 25 to 30 years (SOURCE).

Can You Run a Natural Gas Generator 24/7?

Yes, a solid natural gas generator can run 24/7, you just need to maintain a proper supply of the natural gas.

Don’t let the generator run for weeks or months, the engine and other vital parts of the machine also need a rest.

Do Natural Gas Generators Need Maintenance?

Yes, like other generators natural gas gen-sets also need maintenance.

Why Are Diesel Generators Preferred?

Diesel machines are preferred over natural gas, LPG, or gasoline generators for various reasons like optimum/stable power, lower maintenance cost, and longevity.



Kashif has been a valuable asset to the electric generator industry for over 5 years. Now, As a skilled energy engineer, he’s been on the front lines of diagnosing problems, fixing broken parts, and performing routine maintenance tasks to keep generators running smoothly.

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