How Loud Is An Onan Generator? (ALL FACTS)

How Loud Is An Onan Generator

Have you ever wondered how loud is an Onan generator? Look no more. We´ve got you covered.

Whether having a generator to power your RV is a necessity for you or a luxury, noise level is an important factor to consider.

How Loud Is An Onan Generator? Onan generators come stock in most RVs, and fall a bit under the National Park service noise restriction requirements of 60 decibels at 50 feet.  However, the noise levels of a standard RV generator against the Onan QG 2800i is on average 9 decibels quieter than a “standard” RV generator.

Noise Restrictions

Generators are not known for being quiet neighbors. A common topic of RV camping forums is “How do I make x generator quieter?”.

The National Park Service requires that generators not exceed a noise level of 60 decibels 50 feet away from the source, a sound level somewhere between a quiet office and a normal conversation:

(1) Operating motorized equipment or machinery… in a manner: (i) That exceeds a noise level of 60 decibels measured on the A-weighted scale at 50 feet…”

The law describes various noise-causing devices and goes on to state that noise levels below 60 decibels are prohibited if they are considered unreasonable to the nature of the location, what time of night (or day) it is.

The original purpose the area in question was created for is also taken into account.  The effect on other park users is considered, as well as the type conduct that is considered “prudent”.

Noise-level may not be the first thing you think of when setting out to purchase an RV generator but, given noise restrictions, it could end up being a hugely important factor in your enjoyment of both your RV and your surroundings. 

Read also: How to Fix Fault Code 14 on Onan Generator (Always Works!)

What is An Onan Generator, and How Loud Is It?

Onan generator are powerful enough to run normal-sized appliances while being fuel-efficient and easy to install.  They can help your RV feel like a home away from home. 

Onan generators are designed to be wired into your RV and to use fuel directly from your RV fuel tank, yet they are as quiet as some smaller, and famously ‘quiet’ (for a generator) models that are not made to be hardwired to your vehicle. 

What Are Decibels?

Sound is created when objects vibrate. These vibrations create waves of energy, transferring the sound through various mediums. The air pressure change caused by the vibrations, or frequency, is measured in Hertz. The more frequently the waves repeat, the higher the pitch of the sound.

The change in air pressure created by the vibrating object is measured in decibels (dB). The more energy there is being transmitted in the waves, the louder the sound. Decibels are a measure of loudness. 

9 dB may seem like a smallish number, but it’s actually significant. An addition of 6 dB means double the measured sound pressure.

Humans perceive an increase of 6-10 dB as being almost twice as loud. For example, the difference between a normal conversation and a vacuum cleaner or hairdryer is between 5 and 20 decibels.

An 80-decibel generator can sound as much as four times as loud as a 60-decibel generator. 

Variable Speed Vs. Constant Speed Engines

Most Onan generators are variable speed. Variable speed technology allows an engine to adjust and regulate speed according to the electrical load that is connected to it. This makes it far more economical to run. 

One of the advantages of variable speed units that is especially noticeable over constant speed units is lower noise emissions. Other benefits include reduced fuel consumption, increased time between repairs, and increased power density in a smaller unit.

Variable speed engines are especially useful when a high percentage of low loads is the norm. Constant speed engines are designed to optimize fuel use at high loads, usually above 75%. 

Think of manually shifting gears in a car. A slower running engine saves fuel, and so the driver attempts to optimize fuel use by using the highest possible gear and keeping the engine speed low. 

Read also: How to Use a Generator with a Travel Trailer: Complete Guide

Onan Company

DW (Dave) Onan began building generators in the 1920s with a generator set called the Ten-lite. Ever since the Onan company has been an innovator in power generation equipment. 

Dave used to head out of town, where there was no electric service available. He would sell and wire his generator units, providing light to barns and outbuildings. 

Dave continued to improve his designs over the following decades. After the US entered World War II the Onan Company began manufacturing as many as 70,000 generator sets annually (up from 3500 in peacetime).

For almost three years all of Onan Company’s production went to the US military and its allies. 

The first generator sets made by Onan for motorhomes came out in the early 60s. These first sets were disappointingly loud, vibrated the motorhome, and couldn’t start the electric air conditioners.

But, by 1967, Onan engineers had worked out the major bugs and reliable generator sets were available for the booming motorhome market. 

Onan Corp is currently owned by Cummins Inc. 

Cummins Onan generators come in several models, including variations run on gasoline, propane, or diesel. Their generators are built with sound-controlled or enclosed mufflers. Some come with intake silencers and sound deadening material. 

For further sound control, you can purchase an optional “resonator” that fits over the end of the generator exhaust. These resonators are designed to further lower the decibel level. 

Other Sound-Reducing Suggestions

If you’re looking for some ways to further reduce the decibel levels of your generator, there are a few things you can try. 

  • Make sure the pipe clamps on the exhaust are not in contact with the generator support frame.
  • Line the inside of the generator compartment lid with fiberglass insulation or other noise-dampening insulation such as Dynamat.
  • Install vibration isolators where the corners of the generator unit are bolted down.
  • Install acoustic rubber pucks or a thick rubber mat under your generator unit to help isolate vibrations. 

 In modern RV generator installations, some or all of these features, or similar solutions, may already be in place. 

Which RV Generator Is The Quietest?

Which RV Generator Is The Quietest? With 58 decibels, the A-iPower SUA2000iV 2000 Watt Portable Inverter Generator Quiet Operation is one of the quietest RV generator out there.

I really like this A-iPower SUA2000iV. It’s not terribly expensive but gets amazing reviews. Just follow the link to Amazon where you can see current pricing.

👉 Purchase: If you are interested in this A-iPower SUA2000iV then just follow the link to Amazon where you can see current pricing.

In Conclusion

While the loudness of generators is legendary, many times they are necessary for portable living situations.

The Cummins Onan generators may be some of the quietest large generators on the market today, with noise levels below the noise restriction requirements of the National Park Service.

With an excellent reputation, long history of quality, and readily available maintenance kits, these are a great choice of generator for modern campers. 


Mike Gilmour

Hi, I'm Mike, co-founder, and editor of RV and Playa. My passion is traveling (with my RV) and enjoying the day at the beach (Playa)! Well, I originally created this blog as a way to share what I've learned by experimenting with the RV lifestyle, and I want to help others develop in life through new skills and opportunities.

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