The Complete Guide to Dual Fuel Generators

Power outages are an inconvenience at best and life-threatening at worst. Dual fuel generators provide your home with critical backup power during natural disasters, electrical shortages, or emergencies. 

Unlike traditional petrol generators, you rely on two fuel sources. The dual fuel function provides flexibility to choose the more readily available fuel, but that’s not the only advantage. Dual fuel generators perform better and run longer than their conventional petrol or diesel counterparts.

If you’re unfamiliar with what dual fuel generators can do, this guide has got you covered. Read on to make the best purchase possible and never worry about running out of power again. 

What Is a Dual Fuel Generator? 

A dual fuel generator is a power source that runs on two fossil fuel options. Dual fuel generators can run on either one fuel or a combination of two fuels to achieve optimal efficiency and power output. 

The most common fuel types for dual fuel generators are petrol, propane, and diesel. The engine can shift the usage of one fuel according to fuel level and other parameters. 

You can use dual fuel generators in various situations without worrying about running out of fuel. A dual fuel generator might be a backup power lifesaver if you live in an area prone to power outages. It’s also crucial equipment if you live somewhere remote or prone to natural disasters, where your access to petrol or diesel can be at risk. 

You can’t run dual fuel generators indoors since they produce toxic emissions like carbon monoxide. You’ll need to store and run any fossil fuel-powered generator outside in a sheltered location and run cables to your house to supply electrical power. 

Dual fuel units don’t rely on a single fuel source, making them more flexible and reliable than single-fuel generators. The dual fuel function lets you maximise fuel efficiency by switching between fuels based on various conditions and prolonging your runtime. As a bonus, a dual fuel generator that uses propane as one of its fuel types reduces carbon emissions and particulate pollution. Propane burns much cleaner than petrol or diesel.

What to Consider Before Buying a Dual Fuel Generator 

When searching for a dual fuel generator, it’s easy to become overwhelmed by all the different options. Take the time to research and consider your needs. Use the factors below to find the perfect generator for your home. 

Energy Consumption

First, you’ll need to estimate your energy consumption. For reference, the average UK household consumes about 3,100 kilowatt-hours of electricity per year, which equates to 8,500 watts per day. 

You can determine your household’s daily energy requirements by calculating the wattage of all the devices and appliances you want to power. You’ll want to consider the peak (surge) power consumption and the continuous power consumption. 

For example, when sizing a generator, you’ll need to account for starting wattage — or surge power. The peak watts for turning on a refrigerator can be three to four times higher than its running wattage. If the running watts of the fridge are 50W to 1500W, the starting watts can be anywhere from 200W to 6,000W. 

Power Capacity

Once you know your total power requirements, you can choose a generator with a power capacity that suits your needs. 

Dual fuel generators generally range between 5000 and 12,500 watts of power, although that capacity could be higher. For example, the EcoFlow Smart Generator is a dual fuel generator that can produce 54kWh using petrol or 20kWh with propane (LPG). 

One dual fuel generator will probably not be able to sufficiently power every appliance in your home if you need 30kWh per day. Still, it can provide backup power to your most crucial devices in an emergency. 

Fuel Capacity 

Fuel capacity impacts how much power your dual fuel generator can produce on a single tank. Depending on the model, fuel tanks are typically between 3 gallons and 8.5 gallons. 

With the EcoFlow Smart Generator Dual Fuel, the four-litre tank can produce between 5.4kWh-20kWh of power. The difference in power capacity depends on the tank size and the fuel source.

Noise Level 

Dual fuel generators typically generate between 50 and 90 decibels of noise when operational, with the majority falling between 65 and 75 decibels. Operating on petrol will be louder than running on propane.

Noise can be a concern for various reasons. Some motorhome campgrounds restrict noisy fuel generator use to waking hours, meaning that you might not be able to run a loud petrol or diesel generator to charge your appliances throughout the night. It’s also worth considering if you want engine noise disrupting your sleep while camping, waiting out a power outage, etc.


Size affects the portability and the power output of the generator. Typically, the smaller the device, the less power output it has, but the more portable it is. 

However, some larger generators come with handles or wheel kits. They retain some portability even if they’re too heavy to carry.

Ease of Use 

Dual fuel generators should be user-friendly so that anyone can operate the device. Products like the Ecoflow Smart Generator Dual Fuel prioritise ease of use by simplifying setup, energy monitoring, and refuelling. The Smart Generator also integrates seamlessly with the DELTA Max and DELTA Pro portable power stations and solar generators, and Power Kits.

The Smart Generator offers a propane (LPG) inlet that doesn’t require nuts, bolts, or screwdrivers to connect the tank. Once set up, it can auto-switch fuels within seconds. 

Look for generators with a built-in LCD screen to monitor your fuel and an electric start to turn on the unit. Having to check fuel or start the generator manually can be a hassle. 


Another factor to consider is the maintenance of dual fuel generators. Managing two fuel types means checking the fuel levels in the engine and regularly cleaning the tanks to avoid pipes clogging and unwanted residue. 

The EcoFlow Smart Generator is easy to maintain. With a convenient side-access door, you can quickly swap out oils or replace parts. Sometimes, clever design is all you need to reduce the inconvenience of maintenance. 

5 Must-Have Features of the Best Dual Fuel Generator 

The best dual fuel generators have advanced features to make the user experience safe and meet your power needs, especially during an emergency. Use the features below to gauge the generator’s quality. 

Fuel Monitoring 

Generators require a system to monitor petrol and propane fuel sources accurately. Receiving alerts when fuel is running low lets you know when to refill the tank, especially before disaster strikes.

Additionally, it should monitor the flow rate, informing you whenever maintenance is needed. 

Safety Systems 

Safety should always be a top priority. The best dual fuel generators incorporate built-in safety technology to eliminate risks for the user and protect against potential damages. 

One feature any generator should have is a safety mechanism to prevent carbon monoxide poisoning.

EcoFlow’s Smart Generator’s carbon monoxide detector automatically shuts down when too much carbon monoxide is in the air. It also has an auto-shutdown function to prevent your batteries from overheating in high-temperature environments.

Start and Switch Types 

A generator that’s easy to use and start can be critical in a blackout or natural disaster. 

Most generators turn on using either a manual recoil or an electric start. Recoil involves manually cranking a coil with a pulley system while the electric start powers on with a button. 

Advanced dual fuel generators have an auto-start feature that can automatically start during power outages. It can be a lifesaving feature if you use a CPAP machine or other medical appliance and need the generator to kick on immediately when the power goes out.

The EcoFlow Smart Generator offers four ways to start: auto-start, manual start, app start, and electric start. The app-remote start allows you to start the generator through your smartphone device. 

Also, look for other features like switch-and-go or transfer switch function, which lets you switch fuel sources without shutting off the generator. 

Bluetooth and Smartphone Connectivity 

Bluetooth connectivity gives you added convenience of allowing you to control and manage your generator wirelessly. 

The EcoFlow smartphone app lets you remotely start or stop the unit, switch on Eco mode, control D.C. output levels, and set your battery level for auto-start. You’ll receive real-time alerts whenever the fuel supply is running low. 


Pairing a dual fuel generator with another generator or backup power station allows you to expand your power output and runtime. 

For example, when pairing the EcoFlow Smart Generator with the DELTA Pro or Max, users receive a 40% efficiency gain. The Smart Generator can fully charge the DELTA Pro or Max within just a few hours to expand your total power capacity. 

The Different Dual Fuel Technologies: Propane vs Petrol 

You may be curious about propane versus petrol as fuel sources and wondering which is better. 

Propane is a versatile, clean-burning fuel typically used for cooking or outdoor grilling. Petrol is a highly flammable and transparent fuel made from crude oil. 

Gas burns more efficiently than propane since it produces more heat content per gallon of fuel. Also, propane burns faster than petrol, meaning propane typically has a shorter run time. 

However, propane is easier to store and won’t evaporate or spoil quickly like petrol.

How Long Does a Dual Fuel Generator Run on Gas?

Different sizes and types of generators will determine their runtime. Some can run for eight hours, while others can nearly double that. Smaller generators can run for 2 to 4 hours and require less petrol. 

The runtime varies depending on the petrol consumption rate and the tank size. A dual fuel generator with a petrol tank of 5 gallons can run for about 8 hours. The greater the load (the number of appliances that run on power), the more fuel you use, meaning the shorter the run time. 

However, it’s best to avoid running the petrol continuously for hours since it requires regular maintenance in between, like adding oil and fuel. 

How Long Does a Dual Fuel Generator Run on Propane?

Propane has a shorter runtime than petrol. Most generators run for about five hours on a 20-pound propane tank. 

Some tanks offer greater efficiency allowing the propane to last longer. For example, the EcoFlow Smart Generator features a 4L tank and 1600 to 1800W output, which gives you up to 12.5 hours of runtime using LPG alone. 

How to Choose a Quiet Dual Fuel Generator? 

Whether at a campground or in the wild, the last thing you want is a noisy petrol or diesel generator disrupting your tranquillity and peace.

Fossil fuel generators tend to be loud, so using petrol or diesel as fuel can be a nuisance. The best dual fuel generators feature a low noise output or a noise-dampening function. Quality generators have robust construction and thick shielding to help muffle the sound. Operating on propane also enables the machine to run more quietly than petrol. 

When choosing a quiet dual fuel generator, is to look at the noise level, measured in decibels (dB or dBA). You’ll want to find the most silent generator that’s still powerful enough to fit your electrical needs. 

The dual fuel-generators range between 50 to 90dB of noise output. For reference, here are the decibel ratings of everyday household items: 

  • 50dB: Refrigerator
  • 60dB: Dishwashers or normal conversation
  • 70dB: Traffic or Vacuums
  • 80 dB: Alarm clocks 
  • 90dB: Lawnmowers or hair dryers 

Traditional dual fuel generators run from 65 to 70 dB, while inverter generators create noise between 50 to 60dB. The EcoFlow Smart Generator operates at approximately 56 to 67DB at a 7-meter distance. 

Make sure to look at the specs to see their dB levels and if there are any noise-muffling functions.

What Are the Differences Between Bi-Fuel and Dual Fuel? 

It’s common for people to confuse bi-fuel with dual fuel generators since both rely on two types of fuel. However, that’s where the similarities end.

Fuel Supply

Bi-fuel generators use two fuel supplies but don’t mix during operation. They can switch fuels automatically based on specific parameters. Like dual fuel generators, bi-fuel can use various fuel types, such as petrol, propane, diesel, and natural petrol. 

Dual fuel generators mix two fuel types to run the engine. It draws on the primary fuel source to fill the system before introducing a secondary fuel as a boosting liquid. It allows for an optimal fuel mixture to deliver superior power and efficiency. 

Dual fuel generators are fully capable of functioning on either of the fuel sources alone. There’s also a knob on the backboard of the unit to manually switch between either liquid. 

In short, dual fuel generators work with multiple fuel sources simultaneously, while bi-fuel devices must use one fuel type or the other. 


While dual fuel generators cost slightly more upfront, they are cheaper to operate than their bi-fuel counterparts. Running multiple fuel types improves efficiency, meaning your fuel lasts longer than running on a single fuel type. 


Dual fuel generators are far more efficient at burning fuel. Maintaining an optimal mixture and switching between multiple fuel sources allows you to generate power for longer. When the generator runs out of one fuel, it automatically switches to the other. 


Both generators can be eco-friendly depending on the fuel used. Propane burns cleaner and produces lower emissions than petrol and diesel for power generation. Using a mixture that includes propane will significantly reduce harmful emissions. 


Dual fuel generators provide the flexibility to choose the fuel source best suited for your needs depending on the resource availability, location, climate, cost, and frequency of use. 

For example, propane is readily available. You can store it in tanks longer than petrol. During a natural disaster, it may become difficult to find petrol nearby, making dual fuel generators ideal for any situation. 

If cost is a concern, you can opt for more petrol since it’s typically a cheaper resource than propane. The ability to manually switch and use a mixture between the two gives you complete freedom to manage your generator exactly how you want to based on your situation. 

Dual Fuel Generator for Motorhomes: Is It Worth It? 

Dual fuel generators are a versatile power source that is suitable for more than just emergencies. They are a solid investment for powering up your motorhome to keep your essential appliances running while on the road. 

Being on the road means you may not always have readily available fuel sources. In some remote locations, finding the nearest petrol station can be difficult. When petrol or diesel is unavailable, using other fuel types — like easy-to-store propane — is beneficial. 

Furthermore, you must keep petrol generators at least 20 feet away from your motorhome. If you prefer a quieter and cleaner-burning fuel option, dual fuel generators give you the freedom to choose propane. 

Dual fuel generators can also serve as your solar generator backup and operate seamlessly with the EcoFlow DELTA Max and Pro. Many motorhome fulltimers who prefer a renewable energy source like solar know that sunlight can be scarce, especially during rain and cloudy weather. 

While having a large solar battery capacity certainly mitigates some risks, a dual fuel generator gives you peace of mind knowing you have a last line of defence, even if one fuel or your solar energy runs low. 

The EcoFlow Smart Generator is also compatible with the Power Kits made for motorhomes. It integrates with the power hub, providing intuitive, more efficient power for campers, vans, and class-A and class-C motorhomes.

Is Electric Start Portable Generator a Good Choice for You? 

An electric start generator doesn’t require a pull cord. The machine turns on by simply pressing the start button. 

The button triggers the small battery inside, activating your generator. Generators also tend to have cooling fans which prevent them from overheating. 

An electric start portable generator provides added convenience, especially during natural disasters or emergencies when you need power in a hurry. 


From natural disasters and extended blackouts to camping trips or motorhome fulltiming, dual fuel generators are versatile machines that suit all situations. 

Considering they’re more cost-effective and efficient and have a longer run time than single-fuel generators, dual fuel generators are the perfect solution to keep your appliances running, especially when paired with solar power. 

Switching from petrol to propane or vice versa helps you stay prepared regardless of the circumstance. 

Advanced generators like the EcoFlow Smart Generator provides safety mechanisms like the CO alarm and automatic shutoff protecting you from toxic fumes or battery overload. 

Keeping the above information in mind, you’re ready to determine whether dual fuel generators are the right choice to increase your energy independence. 

EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.


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