Most Efficient Generator Reviews

Updated October 30, 2020

Buying a generator is a significant purchase. Among the many things you need to look into, fuel efficiency is at the top of the list. Then again, you don’t just want it to save on fuel. You also want it to cover your needs effectively, performance-wise. 

In this guide, we’ll be focusing on the most fuel-efficient generator that delivers on performance. Let’s show you how such a generator would look like, what specs it has, and what features it packs. 

As a bonus, we’ll break down the more technical aspects, giving you the knowledge required to judge fairly any generator model you’ll come around of. Buckle up, and let’s get started!

Most Efficient Generators

#PREVIEWProduct
1
Best For Low Budgets
1Westinghouse iPro4200 Generator
Westinghouse - iPro4200 Portable Industrial Inverter Generator
Best For Low Budgets
Westinghouse iPro4200 Generator
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2 Champion 4000-Watt RV Ready DH Series Open Frame Inverter with Quiet Technology Champion 4000-Watt Generator
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3
Best For Higher Budgets
3Honda EU7000iAT1 Generator
Honda_EU7000iAT1 7000 Watt Super Quiet Portable Electric Generator
Best For Higher Budgets
Honda EU7000iAT1 Generator
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4 Sportsman - GEN4000LP Propane Powered Portable Generator Sportsman GEN4000LP Generator
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5 WEN 56200i Super Quiet 2000-Watt Portable Inverter Generator WEN 56200i Generator
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6 Champion - 6250-Watt DH Series Open Frame Inverter with Quiet Technology
Best Overall
Champion 6250-Watt Generator
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1. Westinghouse iPro4200 Generator

Highlights
  • Portable gas generator with recoil start and 4-gallon fuel tank.
  • Features 3 outlets with rubber covers – L5-30R 30 Amp, TT-30R 30 Amp, and duplex 5-20R 20 Amp.
  • 4-stroke OHV engine with 212cc and cast-iron sleeve.
  • CARB compliant and with automatic low oil shutdown.
Best For Low Budgets
Westinghouse - iPro4200 Portable Industrial Inverter Generator

The Westinghouse iPro4200 – WGen3600 – is a top-quality, highly-reliable inverter generator. With a powerful motor and a nicely-sized tank, it can easily back up your home through outages, power your RV or travel trailer, or keep your power tools running on remote, isolated worksites.

Small and compact, camper and RV ready, it requires minimal maintenance and can be used straight out of the box, since it comes with oil. At a 50% load, it can last you for over 13 hours, with an impressive noise level of only 69 dB. At a 25% load, it will work for up to 18 hours!

Even though it only features recoil start, you’ll notice that it starts right off the bat, most often at the first pull. It features a solid construction, it is backed by a 3-year warranty, and it also comes with lifetime support. All these make it an excellent choice, without a doubt!

Specifications

Size:
24 x 20.5 x 20 inches
Voltage:
120 V
Wattage:
4650 peak watts
Noise Level:
64 dB
Output:
4650 peak watts / 3600 running watts
Power Source:
Gasoline

Pros

  • Impressive runtime at 50% load with low noise level.
  • Solid construction that requires easy maintenance.
  • Packed with plenty of advanced features that make it versatile.
  • Backed by a 3-year manufacturer warranty.

Cons

  • No electric push-button start, only recoil.
  • Requires changing the oil after 20 hours.

2. Champion 4000-Watt Generator

Highlights
  • This generator has a power level of 4000 starting watts and 3500 running watts, which provides a total runtime of 17 hours.
  • It is an inverter generator with clean, efficient power. It has three 120V outlets – two 20A and one 30A – as well as a 12V DC outlet and a USB adapter. 
  • This model has an economy mode feature, which helps to reduce fuel consumption and extend the runtime. 
  • It has an open frame design that is light and easy to carry.

Champion’s 4000 watt generator is a reliable option for camping or basic household power generation. It is an inverter generator that produces clean power suitable for electronics like laptops and cell phones. It is very affordable for an inverter generator, so it’s a good option if you need clean power, but don’t want to splash out for a more expensive model.

This generator has a respectable runtime of 17 hours with a 2.9 gallon fuel tank. The engine is a 224cc Champion model that produces 4000 starting watts and 3500 running watts. A low oil shutoff sensor turns the generator off when oil levels drop to prevent safety issues. It comes with a range of outlet options for a variety of different types of electronics, and the control panel is very simple to navigate.

It has an open frame design, which you would expect from a more traditional generator, but it is relatively light and can be carried around. Champion makes compatible parallel kits, which allow you to connect this model to a larger generator for increased power. There is also an economy mode to help you save energy. Not only is this mode very efficient, but it helps your generator last longer.

Specifications

Size:
20.5 x 17.9 x 17.7 inches
Voltage:
120V
Wattage:
4000 starting, 3500 running watts
Noise Level:
64 dB
Power Source:
Gas

Pros

  • Since it is an inverter generator, this model works well with many different types of electronics, and has a wide range of outlets to support them.
  • It has a noise level of 64 decibels, which is relatively quiet for a generator of this power level.
  • It has an efficient design that is relatively lightweight, and a control panel makes it easy to navigate the various functions that the generator offers.
  • You can connect this generator to other inverter generators using Champion’s parallel kit, which is sold separately. This is a great way to increase your power.

Cons

  • Some users have reported issues with mild oil leakage.

3. Honda EU7000iAT1 Generator

Highlights
  • 7,000-watt capacity
  • Switchable between 120V and 240V
  • Compact design
  • Large 5.1-gallon fuel capacity
Best For Higher Budgets
Honda_EU7000iAT1 7000 Watt Super Quiet Portable Electric Generator

Honda is a reputable Japanese brand that has a long track record of producing vehicle engines. This means that their EU7000iAT1 portable generator also embodies the same quality that their vehicle engines are known for. Outputting up to 7,000 watts at peak and with 5,500 watts rated capacity, this generator can provide power for your electronics and appliances if you don’t have a lot to run. It supports adjustable voltages between 120V or 240V, which gives it a rated max output of 58.3A at 120V.

This is the generator with the longest endurance among the rest on this list, as it has a large 5.1-gallon fuel capacity—allowing it to run for up to 18 hours at ¼ its rated capacity, and up to 6.5 hours at its rated load. You also won’t have to worry about noise as this only generates up to 58 dBA at its rated load.

Specifications

Size:
33.4in x 27.6in x 28.4in
Voltage:
120V/240V
Wattage:
7000W max, 5500W rated
Noise Level:
58dbA (full load), 52dbA (1/4 load)
Output:
58.3/29.1A max, 45.8/22.9A rated (120V/240V)
Power Source:
Gasoline

Pros

  • Long-lasting with up to 18 hours of use
  • Low-noise, ultra-quiet operation
  • Inverter technology allows safe operation for sensitive equipment
  • Switchable output voltage for more versatility

Cons

  • Might not be suitable for extra hot climates
  • Recoil starter can be challenging to use

4. Sportsman GEN4000LP Generator

Highlights
  • Propane generator with recoil start, compatible with 20-pound fuel tanks.
  • Features 3 outlets, one for 12V DC and two for 120V AC.
  • Equipped with a 4-stroke, 7 HP OHV engine.
  • Can run for up to 10 hours at 50% load.

This portable propane generator from Sportsman with a 20-gallon tank and recoil start is dependable and friendly with the environment! The three built-in outlets are more than enough for powering a wide range of small appliances, electronics, lights, and even some power tools. 

So, whether you’re considering it as a backup for your home or a power source in a camp or on a construction site, you can’t go wrong with it. The 7 HP engine will keep it running for up to 10 hours with a 50% load. All while the noise will stay at a reasonable level of 68 dB, which, by the way, is softer than your vacuum cleaner. 

Built for reliable performances and powered with the most eco-friendly energy source, Sportsman’s generator is lightweight, starts right up, runs quietly, and comes at a very good price. You’ll probably have a hard time settling for a different model!

Specifications

Size:
19.5 x 17 x 23 in
Voltage:
120 V
Wattage:
7000 peak watts
Noise Level:
68 dB
Output:
7000 peak watts / 3250 running watts
Power Source:
Propane

Pros

  • Good power output and environmentally friendly.
  • Runs with a low noise level.
  • Convenient operation and easy to refill.
  • Ideal for campsite or construction power tools.

Cons

  • Non-CARB compliance makes it unusable in California.
  • Very short, 90-day general warranty.

5. WEN 56200i Generator

Highlights
  • Produces 1600 rated watts (2000 surge watts).
  • Eco-mode feature to adjust fuel consumption. 
  • Long runtime (9.4 hours at quarter load).
  • Limits harmonic distortion so can safely run laptops, tablets and phones.

This is a great option if you’re looking for a generator for camping trips, as this model is portable, compact, and quiet, running at 51dB at quarter load. 

Weighing 48 pounds it’s easier to move this inverter generator around as needed, and although the fuel tank holds only 1 gallon, it will run for over 6 hours at half-load. Harmonic distortion is limited to less than 1.2%, so it’s safe to run more sensitive electronics such as laptops and tablets, and there’s even a USB port. Alongside this are two three-prong 120V and one 12V DC ports. 

We like the Eco-Mode, which adjusts the generator’s motor and therefore the fuel consumption when items are plugged and unplugged. The output is limited to 1600 rated watts, but if you need more power you can link up a second generator using a connection kit (not included). The two-year warranty gives you added peace of mind.

Specifications

Size:
18 x 11 x 18 inches
Voltage:
120V
Wattage:
1600W
Noise Level:
51 dBa
Output:
1600 rated watts / 2000 peak watts
Power Source:
Gasoline

Pros

  • Compact and portable design, ideal for camping or worksites.
  • Extremely quiet operation at 53dB at quarter load.
  • Four outlets including a USB port.
  • 2 year warranty.

Cons

  • Relatively low output, so can only handle a few devices simultaneously.
  • Oil needs to be changed after the first 20 hours of use.

6. Champion 6250-Watt Generator

Highlights
  • 5000 Watt open-frame inverter generator running on gas, with recoil start.
  • Features four outlets – one L14-30R 30 Amp, two duplex 5-20R 20 Amp, and one automotive 12V DC.
  • Champion 4-stroke engine with 301cc and 4.2-gallon steel tank.
  • EPA certified and CARB compliant, with a 3-year limited warranty.
Best Overall
Champion - 6250-Watt DH Series Open Frame Inverter with Quiet Technology

An inverter generator worthy of the Champion title, this 5000 running watts model will catch your eye as being particularly quiet and lightweight. Thanks to the advanced design with an open frame, it runs on as little as 69 dB, meaning it’s 50% quieter than other models at the same wattage. 

With a full tank of 4 gallons, at a 25% load, it will run for about 13.5 hours, with the option to activate Economy Mode. By using the latter, not only will you be able to monitor the power consumption in real-time, but you’ll also use your fuel wiser and contribute to extending the engine life. 

Notably, you can check the voltage, the frequency, as well as the operating hours from its Intelligauge LCD. In case you were wondering, yes, you can confidently hook up even your most sensitive electronics, thanks to the Clean Power mode.

Specifications

Size:
26.6 x 25.6 x 23.7 inches
Voltage:
120/240 V
Wattage:
6250 peak watts
Noise Level:
69 dB
Output:
6250 peak watts / 5000 running watts
Power Source:
Gas

Pros

  • Efficient inverter with lots of advanced features.
  • Facilitates extended runtime with a low noise level.
  • Features intelligauge display for easy voltage and frequency reading.
  • Can power even sensitive electronics.

Cons

  • Not the most affordable option out there.
  • Quick-start guide misses some important information otherwise detailed in the user manual.

Efficient Generator Buying Guide

Fuel Choosing

A generator takes up fuel to power up the equipment. From this perspective, fuel efficiency is the same as energy efficiency. The more you get out of the fuel you’re using, the more you get out of the energy. Below are the most common types of fuel, with their pros and cons at a glance. 

Gas

Gas is a common source of fuel. Easy to obtain, it gives your gas generator increased portability, especially if it’s a smaller unit. Without a doubt, gas is a cleaner and more affordable fuel compared to other non-renewable fuel sources, and it is also significantly efficient, especially when it comes to powering homes. 

It is cleaner, cheaper, and readily available in many places, though still highly flammable and has a shelf life of only 12 months. What’s more, you might discover that many are buying it during power outages, thus becoming more challenging to find. 

Propane

Propane is an attractive choice because of its clean burning, but it also burns really fast. Efficiency-wise, it is definitely not the best choice, and you’ll probably only want to consider it if you’ll run your generator in a remote place where you can hardly bring other fuel types with you. 

At the same time, propane is very easy to store, and sellers prefer to ship it over other fuels because of that. If you’re an eco-conscious buyer and you don’t anticipate a heavy-duty use of your generator, propane could still be the right choice for you. For the best selection of these generators, check out our best propane generator guide. 

Diesel

Diesel is one of the most efficient types of fuel. A diesel generator is less expensive to operate, and it comes with an average consumption of 7% of the generator’s rated output at full load. For instance, a 4-kW generator will have a 0.28-gallon per hour consumption. 

In a nutshell, diesel isn’t just energy-efficient, but also cost-effective. It’s hard to find a type of fuel that scores high in both of these categories, which is why diesel generators are still among the most preferred options. 

Dual Fuel

As they rely on two fuel sources that are already known for their efficiency, dual-fuel generators are among the most tempting choices. After all, they do take the benefits of both gas and diesel power sources. 

The problem is, however, that they are not that common. Even when you do find such a model, you’ll notice its price point is relatively high. From this perspective, you’ll have to ponder if the fuel efficiency is still that high considering the significant upfront investment you’ll have to make. 

Solar

Solar generators give you free energy from the sun, a clean and quiet operation, and they come with low maintenance costs. However, their efficiency is shadowed by the limited power supply, the much higher purchase costs, as well as the very slow recharging pace.

Size

Sizing a generator is something for which you would probably have to consult a licensed electrician. By talking with a specialist to assess your specific needs, you should know what size of generator you will need for the consumers you intend to connect it. 

The rule of thumb is to know the starting and the running wattages for each equipment, to determine the total peak and running wattages you’ll need to draw from the generator. If the total is under the chosen model’s specs, you have picked the right size.

Power

Because efficiency is also given by the fuel type, you’ll encounter top-performing, efficient generators within a wide range of power outputs. Some may have as little as 2000 running watts. Others can go to a whopping 7000 watts. 

Just so you know, if you’re interested in a particular generator model, but you’re not perfectly happy with its power, you might have some wiggle room! Many manufacturers also sell optional kits that would allow you to use two identical generators in parallel, so you can double the power!

Noise Level

The noise level is directly impacted by the size of the motor and the power output. An efficient generator is most likely to feature a power output of around 4000 running watts. For such models, the noise level is expected to be around 65-70 dB. For your reference, this is typically the noise level you’ll get from a vacuum cleaner. 

So, while a generator with a noise level under 65 dB is really silent, you shouldn’t worry too much if you get one above this value, either. Of course, the Honda model we reviewed above, with its 52 to 58 dB at 7000 watts, is something out of ordinary! For more generators with low noise levels, make sure you read quiet generator reviews guide.

Starting System

The starting system of a generator can be either manual or electric. If it’s manual, you have to pull a recoil to turn it on. If it’s electric, you have to push a button. Generally, people tend to avoid pull starts. 

Nevertheless, some of the best fuel-efficient generators we tested actually only came with recoil start. As it turns out, they’re not that hard to handle, contrary to the general expectations.

Pricing Range

If you’re aiming for a 4000 watt generator or around that power, the average price will be around $1000. Occasionally, you’ll bump into a model at around $500-$600, and while it could make a more than decent choice, expect it to lack the advanced features of those that are closer to $1000.

Our Verdict

Strictly speaking in terms of fuel efficiency, diesel generators will catch your eye before anything else. But as you keep digging and learn new things about various types of generators, you’ll see that there are plenty of gas-powered models that are well worth your attention, too.

What’s more, you might become interested in dual-fuel options or anything that allows you to make an adjustment to the unit and increase its efficiency. Whatever you do, keep in mind that the fuel type is just one factor that influences what you’ll get from your generator.

At the very least, one should never ignore the accessibility of a particular type of fuel, especially applied to the site where the generator is intended to run!