Pros and cons of having a tri-fuel generator
Is a tri-fuel generator the right choice for you? Given that there are traditional generators that run only on gasoline and dual fuel generators that run on either gasoline or propane, this largely comes down to whether or not the added ability to run your generator on natural gas is important to you.
First off, there are numerous advantages to being able to run your generator off of propane or natural gas rather than gasoline. Gasoline is typically more expensive than either propane or natural gas, and unlike the latter two fuels it will go stale after only a few months. That means that gasoline is a difficult fuel to store if you are keeping an emergency fuel supply in your basement or garage. In addition, in the event of a disaster – when you most need fuel to power your generator – gasoline is the most difficult of these fuels to get. Long lines and high prices are common as gas stations, whereas propane is often in ready supply at stores and natural gas lines often remain intact. Propane and natural gas also burn more cleanly in your generator’s engine compared to gasoline, which means that your carburetor won’t get gummed up as quickly from use and your generator will last longer.
The downside to switching away from gasoline? Lost power. Gasoline typically provides significantly more continuous and surge wattage than natural gas, so keeping gasoline around can be important if you are planning to run numerous high-wattage appliances such as an air conditioner or electric heating system. While on many dual fuel generators gasoline offers higher wattage than propane as well, on most tri-fuel generators gasoline and propane are rated to provide the same amount of power.
The advantage of a tri-fuel generator over a dual fuel generator lies in the added ability to burn natural gas. Although natural gas typically offers the lowest wattage compared to propane and gasoline, natural gas is often the easiest fuel to obtain since most houses have natural gas lines running into them. In most weather-related disasters, these underground natural gas lines remain unaffected – so you can essentially have a cheap, limitless fuel source running into your generator without the need to store fuel at your house or wait in long lines for gasoline or propane.
The main downside to tri-fuel generators is that they are typically more expensive than comparable dual fuel generators. They are also somewhat heavier and – by virtue of being connected to a natural gas line – less portable, so they are not the generator of choice for camping or work sites in most cases.
Important features to consider when choosing a tri-fuel generator
Since a tri-fuel generator is a big investment that should last for years to come, it’s important to think about the ways in which you are likely to use it and match those needs to the specific features of different generators. In our buying guide, we’ll cover everything you need to know about what differentiates tri-fuel generators from one another so that you can make an informed buying decision. We’ll also go into detail about why a tri-fuel generator may or may not be the right choice for your home and emergency power needs.
Wattage and engine
The most important specification to pay attention to when you are choosing any generator – whether a traditional generator or a tri-fuel generator – is the continuous and surge wattage. The continuous wattage is the amount of power that your generator can run continuously, while the surge wattage is the power the generator can output for 2-3 seconds when starting a motor-driven appliance such as an air conditioner or refrigerator, since motors require more power to start than to run them continuously.
On a tri-fuel generator, these rated wattages vary depending on which fuel type you are using. Gasoline provides the highest output wattages – both continuous and surge – while propane provides an equivalent or slightly lower power output. Operating your generator with natural gas typically entails a slight power decrease.
How much power do you need? The answer depends on what devices and appliances you are planning to run using your generator and what fuel source you are most likely to turn to. The continuous output wattage of your generator should be higher than the sum of the required wattages of all the things you plug into it – if this rating is exceeded, the generator will stall. However, be sure to take note of whether any of your appliances – like your refrigerator or air conditioner – have additional surge wattages, since you will need to ensure that the surge wattage on your generator is able to handle this in addition to the continuous wattage being drawn by whatever else you have plugged in.
The engine is also an important consideration here, since this is the part of the generator that is driving the output wattage and fuel efficiency.
The horsepower of tri-fuel generator engines varies greatly among models, and higher horsepower is not always better, since these engines may be louder or less efficient. Most important is the engine’s efficiency, which varies by model and requires doing some research into the generator you are interested in.
Some, but not all, tri-fuel generators come with an automatic voltage regulator, or AVR, system built into the generator. This system, which is found on the Wanco and Kohler generators that we reviewed, monitors the voltage being output by the generator and keeps it within a small range of the rated output voltage of the outlets on the generator’s face. This system is extremely important if you plan to power sensitive electronics, like computers and smartphones, using your generator’s outlets since a small surge in voltage can damage the circuit boards in these devices. However, an AVR system is not required for most large, motor-driven appliances like a refrigerator.
The number and types of power outlets that are built into the face of your tri-fuel generator determine how many appliances and devices, and to some extent which appliances and devices, you can power off of it. Most generators come with at least four household-style 120V outlets, which are used for powering the vast majority of devices. Also important, though, are twist-lock style 120V/240V outlets, since these are required for some large appliances such as refrigerators and freezers. Few tri-fuel generators come with USB charging ports, although these can be somewhat useful for charging small electronics that draw relatively few watts.
Fuel tank capacity
The capacity of the fuel tanks matters primarily if you will be powering your tri-fuel generator with gasoline, since propane comes in its own tank and natural gas is provided through pipelines. The volume of fuel tanks varies greatly among generators, from 15 gallons to only seven gallons on the Winco generator, and is one of the major contributors to how large a tri-fuel generator is. While the fuel tank capacity will determine how frequently you need to add gas to the generator, having a small tank should not be a limitation since you will need a plastic gasoline canister to store extra gasoline in any case.
In addition to features like the automatic voltage regulator system, many tri-fuel generators come with built-in safety feature like a low oil shut off. This type of shut off is important for protecting both your generator’s engine and your appliances, since low oil can damage the engine and cause wild fluctuations in the output wattage of your generator.
While your generator can function as-purchased in most cases, you are likely to need a few small accessories – which may or may not be included with your generator. A wheel kit is essential for making it easy to move your generator around the house, which can be important if you need to switch between a fixed natural gas line and a safe spot to burn propane or gasoline. In addition, you will need a regulator in order to use propane or natural gas – while some tri-fuel generators provide this, not all do. Finally, running your generator off of propane will require a tubing line to connect the propane tank to the regulator, which is often not provided with the generator itself.
A tri-fuel generator is a significant investment, and you should have the expectation that it will last for years to come when you make your purchase. Many manufacturers offer limited warranties on their generators in order to provide peace of mind, although these warranties vary significantly in length – from the three years offered by Wanco and Kohler to the one year offered by Sportsman – and the issues that they cover. Be sure to check not only on the length of the warranty but also on whether other customers have had success in working with the manufacturer to call it in.
Additional features, such as certification by the California Air Resources Board, can be important if air quality is a concern. Good customer service by the manufacturer is also a major selling point, since this provides some strength behind the warranty on your generator.
How to make your single or dual fuel generator multi-fuel
Did you know that you can run a generator on natural gas, low-pressure propane or gasoline without buying a tri-fuel generator? All you need is to get a special-purpose conversion kit compatible with your generator. There are kits designed for Durostar, Honda, and more.