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Best Portable Diesel Generators 2020 – Reviews & Top Picks

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Best Diesel Portable GeneratorDid you know that diesel generators are more fuel efficient and require less maintenance than gas-powered models? They also tend to last longer and save you in cost over time as well. Even better, with a diesel generator that’s portable, you can take all these benefits on the go.

If you’re shopping for a portable diesel generator, you’ll encounter a variety of sizes, prices, and performance levels. While you may want all the advantages of diesel fuel, you may not be entirely sure which product will work best for your needs.

We’ve done the hard work and have chosen and reviewed the top five portable diesel generators, along with handy pros and cons lists to summarize key points. Also, be sure to look over our buyer’s guide for essential tips to help you make a more informed purchase.

A Quick Comparison of Our Favorites

ModelPriceWarrantyEditor Rating
Melton YDG5500W-6EI
small Melton YDG5500W-6EI
Best Overall

Check Price
1 Year4.80/5
Generac 6864
small Generac 6864
Best Value

Check Price
2 Years4.60/5
Onan 8.0HDKAK-1046
small Onan 8.0HDKAK-1046
Premium Choice

Check Price
3 Years4.45/5

The 4 Best Portable Diesel Generators – 2020

1. Melton Yanmar Diesel Generator – Best Overall

Melton YDG5500W-6EI

The easy maintenance, long-lasting, energy-efficient Melton Yanmar portable diesel generator takes the top spot for best overall performance. You can trust the electrical output on this model, thanks to an AVR (automatic voltage regulator) providing steady and smooth power. This generator also has fuel-efficient features, including direct injection to lower fuel consumption.

Able to run between six and 15 continuous hours on a single tankful of diesel, this generator has an open frame that keeps its engine air-cooled. Additionally, the engine and the overall unit rest on inclined rubber blocks, which reduce vibrations and along with a well muffled exhaust, lower the noise level.

This generator comes with a low-oil shutoff and alarm, a short-stroke recoil starter, and pressure lubrication for easy maintenance. Its only drawback may be the higher price and limited portability. It does not come with wheels or a handle and does weigh a significant amount.

  • Easy maintenance
  • Energy efficient
  • Automatic voltage regulator
  • Direct injection
  • Extended running time
  • Quiet operation
  • Low-oil shutoff and alarm
  • Expensive
  • Limited portability

2. Generac Diesel Portable Generator – Best Value

Generac 6864

We chose this Generac as the best portable diesel generator for the money. Although it runs loudly, you’ll get plenty of power with 5,000 running watts to run most of the appliances in your house or your travel trailer.

The Generac has a Yanmar LW Series 435cc industrial-grade diesel engine with air-cooled direct injection, fuel-efficient idle control, and True Power technology for clean, smooth power output. At a 50% load, this generator has a lengthy extended runtime of 32.4 hours on a 12-gallon fuel tank.

The Generac is solidly constructed with a fully welded 1¼-inch steel frame. At 254 pounds, portability takes a certain amount of effort. This hefty generator incorporates an integrated lifting eye into its design, or you’ll need to purchase a wheel kit for easier transport.

Adding to your expenses, you’ll need to purchase a lawn tractor 330 CCA battery in order to operate the single-touch electric start and the fuel cutoff system. We found that the electric start-up works well, but the pull start is not dependable and can be difficult to use.

  • Best value
  • Sufficient power output
  • Air-cooled direct injection
  • Fuel-efficient idle control
  • True Power technology
  • Lengthy extended runtime
  • Integrated lifting eye for transport
  • Heavy-duty construction
  • Single-touch electric start
  • Loud operation
  • Heavy at 254 pounds
  • Wheel kit purchased separately
  • Battery not included
  • Pull start difficulties

3. Onan Quiet Diesel Generator – Premium Choice

Onan 8.0HDKAK-1046

With the ability to run two 15,000 BTU air conditioners and other appliances, as well as unbelievably quiet operation, there is little debate that the Onan generator is our premium choice. Of course, keep in mind that this top-level performance 8,000-watt generator comes at a high price point.

Thanks to computer-controlled variable speed operation, sound-controlling housing, and an intake silencer, the Onan’s 3-cylinder diesel engine runs at a noise level below National Park Service sound level requirements. Its digital voltage regulation system also provides clean, high-quality sine wave electrical output.

Other features include a bottom air inlet and outlet, a three-point and fully focalized mounting system, a USDA-approved spark arrestor, an internal radiator, a heavy-duty air cleaner, a maintenance-free electronic governor, and easy, accessible maintenance points. It also has a waterproof connector for remote operation. This generator meets U.S. EPA and California emissions standards.

Although ideal for camping, you may run into difficulties transporting this 420-pound, closed-construction generator, which does not come with wheels or other portability options.

  • Premium performance and power output
  • Extremely quiet operation
  • Digital voltage regulation for clean electrical output
  • Computer-controlled variable speed operation
  • Vibration-reducing mounting system
  • USDA-approved spark arrestor
  • Heavy-duty air cleaner
  • Easy maintenance
  • Waterproof connector
  • S. EPA and California emissions standards
  • Expensive
  • Heavy at 420 pounds
  • No portability options

4. POWER PRODUCTS Sigma Silent Diesel Generator


At a significantly lower price than the other models on our list, you won’t have to compromise power or quiet operation with the Sigma silent diesel generator. It can supply up to 7,000 watts with a 5,500 running wattage, which means it has the capability to run most appliances. The Sigma’s enclosed frame reduces the noise level to a comfortable 68 decibels.

This generator’s four-cycle air-cooled diesel engine employs direct injection for better fuel efficiency. It also comes with a battery-powered starter and a recoil back-up starter. Once in operation, the Sigma has an extended running time of eight hours at a half load on a full fuel tank with 3.96 gallons capacity.

A fuel gauge is included for your convenience, as well as a low-oil alert, an AC circuit breaker, DC output 12V/8.3 A, and an AC socket. While a voltmeter is included, this generator does not have a component to regulate variable voltage levels, which could damage certain sensitive electronics.

The Sigma is easily transported, thanks to built-in wheels and a handle incorporated into its design.

  • Affordable
  • Powerful wattage output
  • Extremely quiet operation
  • Direct injection for better fuel efficiency
  • Extended running time
  • Low-oil alert
  • Voltmeter
  • Easy transport with wheels and handle
  • No voltage regulation

Buyer’s Guide

Even after reading through the reviews and pros/cons lists, you still may be unsure which portable diesel generator will best fit your needs. These heavy-duty, powerful machines tend to have a higher cost, so it’s important to be well-informed before you invest. We’ve put together a buyer’s guide to highlight why paying more for a diesel generator may be worth it. We’ve also explained helpful features and important components to consider before you make a purchase.

The Benefits and Drawbacks of Diesel Fuel for Portable Generators

You may be in the market for a diesel-fueled portable generator because you know that it has many advantages over gas-powered models. In this section, we’ll discuss the perks of going with a diesel-powered generator, as well as potential drawbacks.

One of the biggest factors for buying a diesel-fueled product is the reduced maintenance. Over the lifespan of your generator, you’ll save both money and time with fewer maintenance issues that require attention and resources. Speaking of lifespan, diesel-fueled generators tend to last longer and have greater fuel efficiency compared to their gas-powered counterparts. They’re also safer to operate, since diesel is less flammable and less explosive.

However, before you make an investment with a diesel product, make sure to double check your budget. Diesel generators often cost more to buy. The availability of diesel fuel and its fluctuating prices may become an inconvenience and an expense. Also, be sure to look at the decibel levels before you purchase a diesel generator. While some products excel at reducing the noise level, most diesel-fueled generators operate louder than gas-powered models.

Essential Tips Before You Buy

When it comes to portable diesel generators, there’s several features and performance levels to consider before you make a purchase. Knowing what to look for and what to avoid can help you choose the best product for your needs.

Wattage output should be among your top considerations, since the point of any generator is to power appliances, devices, and possibly heating/cooling systems. Whether you’re dealing with a power outage or bringing your generator on a camping experience, you’ll need a generator capable of producing up to 7,500 watts or more. With that amount of wattage, you’ll be able to power a refrigerator, laptop, several lights, smartphone charger, home security system, 10K BTU air conditioner, well pump, sump pump, and gas or propane furnace. If you unplugged one of the above appliances, you could run a burner on an electric range or use the dishwasher.

When powering more sensitive electronics and technology, you’ll want to be mindful of the fluctuations in voltage being supplied by your generator. Many top-rated generators employ an automatic voltage regulator to supply a safe, steady, and clean power output. With a voltage regulator, you avoid inflicting damage to your appliances and devices.

As you consider which portable diesel generator to purchase, look for an engine with direct fuel injection for improved efficiency. Other helpful features include a low-oil shutoff to save serious damage to your engine from occurring and an electric starter for convenience. To reduce how loud your generator will operate, be sure to purchase a product with a closed construction, adaptions for vibration, and idle control, as well as components that reduce the noise level.

Finally, if you plan to take your diesel generator on your next outing or adventure, you’ll need to be able to transport it. All the generators reviewed weigh hundreds of pounds. Be sure the one you purchase comes with built-in wheels or has a wheel kit available for purchase. Also, look for handles and other portability options to make transporting your heavy generator possible.

Generac 6864

Featured Image Credit: Generac, Amazon


The Melton YDG5500W-6EI Yanmar Portable Diesel Generator earned our top pick for best overall portable diesel generator due to its easy maintenance and energy-efficient operation. It comes with an essential automatic voltage regulator, an engine that employs direct injection, and a low-oil shutoff and alarm. The Melton has an impressive extended running time and operates quietly. Its only cons are that you’ll pay more for these optimal features, and without handles or wheels, portability is limited.

Our choice for the best value went to the Generac 6864 Diesel Powered Portable Generator. The Generac has sufficient power output at 5,000 running watts. It’s also fuel efficient, with air-cooled direct injection and idle control. The Generac uses True Power technology and has a lengthy extended runtime and a single-touch electric start. Although heavy at 254 pounds, it has a solid construction and an integrated lifting eye for transport. Keep in mind that you’ll need separately purchase both a wheel kit, as well as the battery. This generator is one of the loudest products we reviewed, and be aware that you may encounter pull start difficulties.

The Onan 8.0HDKAK-1046 Quiet Diesel Generator has the power and performance to be our premium choice. Even with an amazing 8,000-watt power output, this generator has an equally unbelievable low noise level. The Onan offers digital voltage regulation for clean electrical output, computer-controlled variable speed operation, and a vibration-reducing mounting system. Additional features include a USDA-approved spark arrestor, a heavy-duty air cleaner, and a waterproof connector. This generator is easy to maintain and meets U.S. EPA and California emissions standards. However, you will pay significantly more for this generator’s high-quality operation. Be aware that it has no portability options.

We hope that our detailed reviews, convenient pros and cons lists, and informative buyer’s guide have helped you learn more about portable diesel generators before you make a purchase. Investing in a portable diesel generator can be an excellent choice to supply ample power to either your house during an outage or to bring the comforts of home on your next travel endeavor.

Featured Image Credit By: Yanmar YDG5500W-6EI Portable Diesel Generator, amazon

About the Author Adam Harris

Hi there! My name is Adam and I write for HealthyHandyman. I have a great passion for writing about everything related to tools, home improvement, and DIY. In my spare time, I'm either fishing, playing the guitar, or spending quality time with my beloved wife. You'll also often find me in my workshop working on some new project!