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Which is Better? Petrol Vs Diesel Generators

Are diesel generators better than petrol?

If you’re looking to hire one or more generators for an upcoming event or festival, or generators are required to power up your mining operation or construction site, you’ll likely find yourself tossing up between a generator that is powered by petrol or a portable diesel generator. If you opt for diesel, you’ll also need to know more about diesel generator fuel consumption and whether it’s cost-effective.

Like most things in life, there are advantages and disadvantages associated with both types of generators. To help you make a more informed decision regarding which type of generator will suit your needs best, you first need to know more about the pros and cons of a petrol-fueled generator versus a portable diesel generator.

What is a Diesel Generator?

To answer the question, “Are diesel generators better than petrol?” we need to learn more about the diesel generator and the petrol generator. Let’s start with the diesel generator.

Diesel generators are a combination of an electric generator and a diesel-powered engine to produce a continuous supply of electricity. They come in many sizes and can be permanent fixtures as a backup power source in a residential building, for example, or a portable diesel generator that can be transported to any location where temporary power is required.

Combustion engine generators that operate on diesel fuel convert chemical energy in the fuel into mechanical energy by rotating a shaft or crank. As diesel fuel is injected into the engine and is mixed with air and compressed, the resulting explosion of expanding gas drives the pistons in the engine. This mechanical energy results in electrical energy being produced by an alternator.

You’ll often find portable diesel generators being used for industrial and commercial applications due to robust build quality, reliability and their ability to generate enormous amounts of electricity.

Diesel Generator Benefits

Fuel Efficiency

Diesel generator fuel consumption is low compared to petrol generators, and this fact alone makes them extremely popular for commercial and industrial use where profit margins need to be considered. The reason diesel generators use less fuel is due to the combustion process. Compression heat rather than spark ignition burns the fuel and results in a diesel-powered motor consuming up to 50% less fuel for the same amount of runtime.

Less Flammable

Safety is always a consideration on work sites, with fire always being a potential danger. Diesel fuel is way less flammable than gasoline, thereby making diesel generators safer to run, particularly for extended periods.

Robust and Reliable

Virtually any piece of machinery, whether it be a vehicle or a generator, that runs on diesel fuel will be more robust. This leads to a more reliable piece of equipment that rarely breaks down and takes a long time to wear out. Diesel motors also operate at lower temperatures than other motors.

High Power Output

With low diesel generator fuel consumption, yet the ability to provide a very high output of power, makes the diesel portable generator the perfect power source for commercial and industrial projects.

Fuel Availability

Diesel fuel is widely available and accessible in most areas, ensuring a steady supply for running the generator.

Fast Start

Diesel generators fire up quickly and start producing electricity rapidly. This is vital in emergency situations when power is needed. Smaller generators tend to have shorter start-up times than larger generators.

Drawbacks of Diesel Generators

Noise and Vibration

Diesel-powered engines can be noisy, and this can apply to diesel generators as well. While noise can be a concern in some locations, it’s not usually an issue on commercial and industrial sites.


Many diesel generators designed for commercial applications can be big and bulky, meaning there needs to be sufficient space to house one or more generators.

Are diesel generators better than petrol generators? Let’s now take a look at petrol-powered generators and their benefits.

What is a Petrol Generator?

Naturally, a petrol generator runs on gasoline rather than diesel. As with diesel, petrol generators also convert chemical energy in the fuel into mechanical energy. As petrol enters the engine, sparks ignite the fuel, forcing the pistons to move up and down and rotate a shaft. The rotor creates a mobile magnetic field around a stationary stator. This results in the generation of a voltage difference between the stator windings, ultimately producing electricity.

Although petrol generators also come in a variety of sizes to suit different applications, they are more suited to and, therefore, more often used for residential and leisure applications, such as backup power for the home or to provide electricity for a caravan or campervan.

To better answer the question “Are diesel generators better than petrol generators?”, we need to now go over the pros and cons of petrol-powered generators.

Petrol Generator Benefits

Quiet When Operating

While diesel motors are known to be quite noisy, petrol-powered generators are quieter when running, which makes them ideal to use at home or when camping.

Petrol is Often Less Expensive

Even though prices do fluctuate, the price per litre of diesel is usually higher than petrol, making petrol generators cheaper to refuel. Keep in mind that diesel generator fuel consumption is considerably lower, though.

Good for Short-Term or Intermittent Use

While not a great choice for commercial projects, the petrol generator is ideal for either intermittent or short-term usage.

Small and Mobile

Many petrol generators can be carried in the back of the car and lifted by two people.

Low Maintenance

Small petrol generators tend to be quite easy to maintain.

Drawbacks of Petrol Generators

Not Robust

While they get the job done for small applications, petrol generators are not robust enough to handle the big jobs, where a generator is being moved from place to place and operating for long periods of time.


Petrol is more flammable and therefore presents a greater fire risk.

Limited Runtime

Petrol generators burn through fuel at a faster rate and which causes them to have a limited runtime. They are not ideal for continuous use.

Petrol Vs Diesel Generators

Are diesel generators better than petrol generators?

Both types of generators have their benefits and cons. Often, the decision about which one is better often comes down to how you want to use it and what you need a generator to achieve. If you just need a generator for backup power at home or for use when camping, then a petrol model might be the best choice.

However, for any type of commercial or industrial use, the best option will always be a diesel-powered generator. They are far more robust, economical to run, can produce the power supply you need for extended periods and are far less likely to break down with continuous runtime.

Why are diesel generators better than petrol? While both types of generators have their pros and downsides, diesel generators are the generator of choice for applications that require a high degree of reliability with a continuous high power output.

Get Generator Hire at Total Generators

Are diesel generators better than petrol? They are for commercial and industrial projects. Talk to the experts at Total Generators about the advantages of diesel generators and your options for hiring the right generator for your project. Contact us today.

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