Best fuel efficient generator: How to Find the Most Fuel-Efficient Portable Generator

Are you looking for a portable generator? There are several different generators divided into multiple categories. They can be divided by price point or by fuel. The most common fuels tend to be natural gas, propane, diesel, and gasoline. Natural gas isn’t as common in the United States as it might be in other countries. The fuel efficiency of the generator is generally rated by the gallons consumed per hour at certain levels of work. For example, a 5,000 watt gasoline generator might consume 1.25 gallons per hour at full load.

You’re going to have different needs based on how much fuel you might have available, if the fuel is being used for other sources, and how much power you might need. For example, someone who is looking to tailgate before a football game will need a different type of generator than someone who wants to power their home during a power outage. Portability, power output, fuel consumption, and decibel levels will all factor in.

I’ve gathered all of the data you need for the different types of generators. Before we get into all of the reviews and information, here is a quick run-down of the most efficient generators in each fuel type.

Below, you’ll find reviews of those generators as well as their competitors.  Let’s get right into it.

What size generator do you need? Estimate Your Power Needs

Before I get into the different types of generators, you’re going to need to know how much power you need. If you’re using your generator for camping or tailgating, you’ll need less power than someone who is using it to run their household appliances. Furthermore, there are two different types of wattage; there are running watts and starting watts. Running watts are the amount of power a device needs to operate normally. The starting watts is the amount of power some appliances need to start. Oftentimes, this is a higher amount of power to get the appliance operational. Also, the appliances might need more power when they’re under a heavy load. For example, the running watts of your freezer might be one thing, but it will spike when the freezer needs to actually bring down the temperature inside the freezer.

Refrigerator/Freezer 600 Running Watts 2200 Starting Watts
Microwave Oven 625 Running Watts 0 Starting Watts
Box Fan 200 Running Watts 0 Starting Watts
60 Watt Lightbulb 60 Running Watts 0 Starting Watts
Washing Machine 1120 Running Watts 2250 Starting Watts
Coffeemaker 1000 Running Watts 0 Starting Watts
32” LCD TV 50 Running Watts 0 Starting Watts

These are some pretty standard items that you might run from your generator. To calculate the amount of wattage you’ll need from your generator, you should add up the total amount of running watts for everything you will be running. Then add that number to the highest number of starting watts needed. That will give you an estimate for how much wattage you’ll need.

If you don’t see an item comparable to something you want to run, you can usually look up the amount of wattage consumed on the item’s website. Alternately, you can find it in the owner’s manual or on the tag. If you don’t see the wattage, you can calculate it. Multiply the volts by the amps to get the running watts of each item you will run.

Gasoline Generators

Gasoline is the most common and most easily-sourced fuel. You will be able to find it wherever you go and along the way to your destination. It can be somewhat cumbersome to lug around gallons of gas, but you never have to worry about running out of fuel. A quick trip to a gas station will top you back off.

So, if you’re looking for a generator that will simply use the least amount of gasoline possible, you should seriously consider an inverter generator. In a typical generator, every turn of the engine turns a conductive coil in a magnetic casing to produce alternating current (AC). To produce steady AC, the generator typically needs to turn at 3,600 RPM. That will raise the fuel consumption considerably.

Alternately, an inverter generator uses a device that converts the AC into direct current (DC). The DC is then converted again into AC. The mechanism is somewhat complex, but suffice it to say, all of that converting allows you to use less fuel. When you need less power, the inverter generator consumes less fuel. When you need more power, it consumes more. So why doesn’t everyone just use inverter generators?

The Yamaha EF2000iSv2 inverter generator is an incredible generator. It is lightweight, hyper portable, and very efficient. Everyone doesn’t use inverter generators because they’re pricey. The Yamaha model is one of the best inverter generators.

Yamaha EF2000iSv2 Wen 56200i Westinghouse iGen2200 Honda EU2200i
$$ $ $ $$$
2000W maximum output 2000W maximum output 2200W maximum output 2200W maximum output
51.5 dba at ¼ load 51 dba at ¼ load 52 dba at ¼ load 48 dba at ¼ load
10.5 hours on 1.1 gallons at ¼ load 10 hours on 1 gallon at ¼ load 12 hours on 1.2 gallons at ¼ load 9.6 hours on one tank at ¼ load
44.1 pounds 48 pounds 46 pounds 47 pounds

Based on these four models of inverter generators, the most efficient generator is hard to choose.

  • If you want the quietest generator possible, the Honda model is quieter than the others.
  • If you want the lightest generator, the Yamaha model is a better choice.
  • If you need maximum output, Westinghouse and Honda both produce comparable models. The price point could be the deciding factor.
  • The least expensive options are the Wen model and the Westinghouse.

If you need the most power output possible, you’ll need to consider a more traditional generator.

Westinghouse WGen7500 Pulsar Products PG10000B16 DuroMax XP12000E DuroStar DS4000S
$$ $$ $$$ $
9500W maximum output 10,000w maximum output 12,000W maximum output 4000W maximum output
16 hours on 6.6 gallons at ¼ load 16 hours on 8 gallons at ¼ load. 10 hours on 8.3 gallons at ½ load 8 hours on 4 gallons at ½ load
192 pounds 209 pounds 260 pounds 92 pounds


As you can see from the above chart, the traditional generators produce far more power than the inverter generators. They also cost about the same, with many of them being significantly less expensive. For example, the least expensive model, the DuroStar, still produces twice the peak power of the inverter generators.

  • If you’re looking for the generator that consumes the least amount of fuel, the DuroStar is the model for you. It’s also the lightest model; it’s about half the weight of the other models. That would make the DuroStar model a great choice for tailgating or camping.
  • However, if you need to run more appliances in your house, you’ll need far more wattage. The DuroMax model will produce the most peak wattage; however, it is also the heaviest and consumes the most fuel.
  • The WestingHouse model is probably the best compromise between fuel efficiency and power. It produces close to 10,000W at peak output but is more fuel efficient than the Pulsar Products model.

Diesel Generators

Diesel is a popular fuel for generators of many different sizes. You might be wondering why someone would choose a diesel generator instead of a gasoline one. There are several different reasons. Diesel is often thought of as the fuel for farm equipment and trucks. That’s actually one of the reasons it is a great fuel for generators.

Diesel is often available during disasters because it is the fuel needed for military equipment and shipping trucks that are vital to emergency response. That means that you’ll likely be able to find it even during a disaster.

Diesel generators are often more fuel efficient than gasoline generators; furthermore, diesel can cost less. Diesel fuel is actually bifurcated into road fuel and off-road fuel. It is essentially the same fuel but dyed in different colors. Off-road fuel used for farm equipment is not taxed as much as fuel for road use. Since your diesel generator could run on off-road diesel, it could be considerably more affordable than other types of fuel.

Generac 6864 Dayton Portable Generator
5500W Maximum Output 9160W Maximum Output
32.4 Hours on 12 Gallons at ½ Load 12.8 Hours on 2.6 Gallons at ½ Load
254 Pounds
$$$$$$ $$$$$$$$

As you can see, the maximum output of most of the diesel generators is actually lower than the gasoline generators. That is similar to the higher torque and low-end power of diesel vehicles over gasoline vehicles. However, they’re much more fuel efficient. With the exception of the Generac model, they have smaller fuel tanks with similar amounts of running time.

  • The most fuel efficient of the generators is the Dayton model.
  • The generator that will go the longest without refilling is the Generac model.

You should make sure you factor in the amount of fuel each generator can hold. Diesel fuel weighs about seven pounds per gallon. Therefore, if you carry 12 gallons of diesel with the Generac model, you’ll need to add 84 pounds to the weight of the generator.

As far as using the least amount of fuel, the Dayton model uses the least fuel. However, you will have to refill it more often, and it costs more than some other models.

Propane Generators

While propane is mostly synonymous with grilling during the summer, it’s becoming more popular for generators. There are some obvious reasons propane is becoming a popular fuel for portable generators. Propane generally costs about half as much as gasoline per gallon. Also, propane is easier to store and move.

Gasoline and diesel are liquids; therefore, they’re very difficult to move. They’re also prone to spilling. That can be a dangerous and time-consuming accident. Propane is stored in self-contained tanks that cannot spill. If you were to somehow spill the propane, it would immediately evaporate.

Also, propane has a much longer shelf life than diesel or gasoline. Diesel can be stored for about 18-24 months. Gasoline is good for about 12 months. Propane will last indefinitely as long as your tank is in good condition.

Propane is also a great fuel for emergency generators. You can generally find propane even during an emergency. Moreover, propane tanks can be filled without electricity. It’s a clean-burning fuel that produces engines typically quieter than gasoline or diesel.

All Power America APG3560 Champion 7500-Watt Dual Fuel DuroMax XP12000EH Dual Fuel Pulsar Products PG10000B16 Dual-Fuel
6000W Maximum Output 8400W Maximum Output 12000W Maximum Output 9000W Maximum Output
75 dba 74 dba
8.5 hours 5.5 hours 20 hours 12 hours
213 pounds 202 pounds 269 pounds 218 pounds

As you can see from this chart, the propane generators tend to need more refills than diesel generators, but they’re comparable to gasoline generators. All of the durations listed are for the standard barbecue grill size propane tank, which is 20 pounds. You’ll need to replace the tank more than you would need to refill a diesel generator but the switch is much easier.

The most efficient propane generator listed is the DuroMax dual fuel model. The model is efficient because it will produce the longest amount of power with one propane tank. Furthermore, it is a dual fuel generator.

Dual Fuel Generators

The final kind of generator that many people is a dual fuel generator. As the name suggests, dual fuel generators are capable of running on two different types of fuel. These are the most common propane generators. Generators that run solely on propane are slightly less common. Dual fuel generators have several advantages. One profound advantage is obviously the versatility.

Propane and gasoline is the usual combination. Propane is available during emergencies, power outages, and anywhere that sells supplies for a barbecue grill. Propane can also be convenient if you are already using a gas grill. You won’t have to worry about bringing multiple kinds of fuel with you. On the other hand, gasoline is useful because it is available on every roadway in the United States. You can find gasoline everywhere you go.

Is there a difference between the fuel outputs? Yes. Propane is a less efficient fuel than gasoline. It burns cleaner but it also burns faster. That means that it won’t last as long as gasoline or produce as much power. Typically, a dual fuel generator will produce about 1000 watts more power using gasoline than propane. However, it will be much louder and produce much higher emissions while running gasoline.

Propane is useful, especially if you are going to be in a national or a state forest. National forests, and most other public areas, have very strict rules about which types of engines you can use on their grounds. Some of them have emissions standards, but usually, they are trying to prevent devastating fires. That means that they might ban gasoline engines completely, or they might require a spark arrestor to keep the engines from starting fires. Typically, propane engines are allowed. Therefore, a dual fuel generator might be the best option for someone who plans to use it in national parks.

What Have You Learned?

So, the original question was which portable generator is going to be the most fuel-efficient. There are several different ways to answer that question. Generally, a diesel generator is going to be the most fuel efficient. Gallon for gallon, diesel engines burn the least amount of fuel to produce power. However, diesel generators do not produce the high wattage of gasoline generators.

Therefore, if you want to produce the most wattage for the least amount of fuel, you should be looking for a fuel-efficient gasoline generator. Gasoline produces the most power but it consumes a lot of fuel. If you want a good middle ground between fuel efficiency and power output, you are probably better off choosing a propane generator.

The Winners

Portable generators are typically used for recreation where there is no electricity, job sites that have no electricity, and power outages. The differences between types of generators will determine what they are best for.

Best Recreation Generator

The best recreation generator is likely the Honda EU2200i. It is a lightweight generator with an electronic ignition for easy starting.

The Honda EU2200i portable inverter generator

The Honda EU2200i portable inverter generator

The inverter technology allows you to change to a fuel-saving mode when you do not need to put it under heavy load. Furthermore, it is as quiet as the average conversation. That makes it a great tailgating generator or a generator for an RV. It delivers enough power to run televisions for hours, lights, and even some outdoor fans. Tailgaters and RV enthusiasts love this generator. Check the current price of the Honda EU2200i here on Amazon.

Pros Cons
Lightweight Can be underpowered
Electronic Ignition Small gas tank
Fuel Efficient

I give this generator 4 out of 5 stars.

Best Jobsite Generator

For the jobsite, you’ll need something large and powerful. The sound levels are not as important and the weight is less of a concern.

The Generac 6864 - off road diesel generator

The Generac 6864 – off road diesel generator

You can likely take it to and from the jobsite in the back of your truck. That’s why the Generac 6864 is the best generator for a construction site or agricultural use. Since it runs on off-road diesel, you’ll always have fuel available and won’t have to bring a different kind of fuel with you. It’s a fairly heavy and loud generator, but it will deliver power for over 24 hours if you need it. Check the current price of the Generac 6864 here on Amazon.

Pros Cons
Powerful Low Peak Wattage
Runs on Diesel Heavy
Huge Fuel Tank Loud

I give this generator 3.5 out of 5 stars.

Best Emergency Generator

The best generator for a power outage is DuroMax dual fuel generator.

The DuroMax XP12000EH Dual Fuel generator

The DuroMax XP12000EH Dual Fuel generator

It provides an incredible amount of power and can run on propane or gasoline. Propane is a great fuel for an emergency generator because propane has a much longer shelf-life than other fuels. Also, being able to run on gasoline is a huge benefit since it is readily available. Check the latestprice of the DuroMax XP12000EH Dual Fuel here on Amazon.

Pros Cons
High Wattage Expensive
Dual Fuel
Easy to Use

I give this generator 4 out of 5 stars

Best Budget Generator

Finally, the best and cheapest generator is the Westinghouse WGen3600v.

The Westinghouse WGen3600v a budget priced generator

The Westinghouse WGen3600v a budget priced generator

It is the cheapest generator in this review at the time of writing. It is cheaper than other models for several reasons. It has only a pull start instead of an electronic ignition. However, owners of this model have said that it starts reliably on the first or second pull. The model is a little bit loud at 62 dba at half-load and weighs about 112 pounds, but those are the trade-offs you make when you choose the cheaper option. Some have said that the pull start is a bit awkwardly placed and the generator does not come with a wheel kit. You’ll have to get the wheels separately. Check the latest price of the Westinghouse WGen3600v here on Amazon.

Pros Cons
Affordable No Electronic Ignition
Reliable Heavy
No Wheels

I give this generator 3.5 out of 5 stars.

Related: Best portable inverter generators under $300, $400, $500, $600, $700, $800 & $1000

Most Popular Generator

The most popular generator, based on customer reviews, is the Westinghouse WGen7500.

The Westinghouse WGen7500 a very popular generator

The Westinghouse WGen7500 a very popular generator

This generator has a 420cc four-stroke engine, which will provide consistent and smooth power. It has numerous outlets for running extension cords. It has both an electric ignition as well as a pull start. There is an easy to use LCD display. Everything about the generator is intuitive and easy to use. That’s why it’s so popular. It’s also made from solid steel, which makes it very sturdy and durable. However, all of that steel makes it large and heavy. It’s probably too heavy for some people to move easily. It also doesn’t fit in some RVs. However, when it comes to an all-around workhorse, the WGen7500 is well liked. Check the latest price and customer reviews of the Westinghouse WGen7500 here on Amazon.

Pros Cons
Reliable Four-Stroke Engine Heavy
LCD Display Large
Electronic Ignition Underpowered in Some Circumstances

I give this generator 4.5 out of 5 stars.


Hopefully, all of this has helped you choose the right generator for your different needs. If you still need some more information, you can find information on portable generators from these reliable sources:


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