A portable generator can run for around 8 to 18 hours on a full tank of gasoline.
This type of generator can also only run continuously for this long since you need to refuel it.
A standby generator can run continuously for up to 500 hours on propane or natural gas if you maintain it well.
To maintain the machine you want to check when things like oil changes are necessary.
Additionally, all these duration estimations for how long a generator can run depend a lot on details like:
- Generator type
- Fuel source
- Generator build quality
If you are unsure, you want to check your generator manual or contact customer support. This will ensure you get to the upper limits of how long a generator lasts.
How long can a generator run on different fuel sources?
A portable gas generator can typically run for 8 to 18 hours on a full tank of gas.
As you can tell, there are big differences in run times. Even between portable generators in the same category.
Additionally, generators that run on propane can run longer with bigger fuel sources.
In these cases, you can use a calculator to see how fast your generator consumes these fuels and how long it will last on a certain propane tank.
Natural gas generators only tend to be limited by how long the machine can run continuously. More on this later in the article.
How long can a generator run on gas?
According to my research of hundreds of gas generators, a generator will typically run for 8 to 18 hours on a full tank of gasoline.
The exact number of hours will depend on the generator tank size, power capacity, and fuel efficiency.
How long will a generator run on 5 gallons of gas?
A generator will run for around 11.25 to 40 hours on 5 gallons of gas.
The exact duration will depend a lot on the generator power output.
For example, 2500 peak watt generators tend to generate around 2000 running watts.
It is normal that these will run longer on 5 gallons of gas than a 9000 watt generator that produces 7250 running watts.
There is a limit to how much electricity you can get out of 5 gallons of gas. By only producing lower amounts of wattage, a small generator will run longer.
How long will a generator run on 1 gallon of gas?
A generator will run for around 2.25 to 8 hours on a gallon of gas.
These are still rough estimations. The design and size of the gasoline generator will influence the duration a lot.
How long can a generator run on propane?
A generator can run on propane for as long as the fuel tank and equipment build hold out.
Portable generators can typically run for around 9 to 22 hours on a 20 lb propane tank.
Even with a bigger propane tank, there is a limit to how long you can run these continuously (later in the article more about that).
Standby propane generators use around 1 to 2 gallons of fuel an hour depending on the load.
This means a standby propane generator would only run for 2.3 to 4.6 hours on a 20 lb tank.
How long can a generator run on a 20 lb propane tank?
A portable generator can typically run for around 9 to 22 hours on a 20 lb propane tank.
Similar to gasoline generators, the output of the propane-compatible models will influence the numbers a lot.
Some small propane inverter generators can even run up to 34 hours on a 20 lb propane tank.
On the other hand, bigger standby propane generators with bigger outputs will only run for 2.3 to 0.6 hours on a 20 lb tank.
At least if you apply a similar % of the total load to your calculations. Not the same wattage output.
How long can a generator run on 100 gallons of propane?
A standby propane generator will run for about 12.5 hours to 50 hours on 100 gallons of propane.
The actual power capacity and output will influence the duration a lot.
For a standby propane generator, you generally want to estimate around 1 to 2 gallons of fuel an hour at 25% to 100% load.
Individual models can still vary.
When it comes to portable propane generators, the guidelines on how long you can run them without rest will typically be the limiting factor.
Not the 100 gallons of propane.
How long can a generator run on diesel?
A standby diesel generator can run for around 10 to 50 hours. The exact size and fuel tank will influence the number of hours a lot.
Smaller portable diesel generators run for around 5 to 30 hours.
This is again a big duration range due to the differences in diesel generator power output, fuel efficiency, and tank sizes.
How long can a generator run on natural gas?
According to Petro, a standby generator can run for up to 500 hours continuously although this is generally not recommended.
When it comes to natural gas generators, the fuel source is typically not the limiting factor.
That means other details like the need for oil changes or letting the engine cool down influence the actual duration.
Portable natural gas generators can often run for around 24 to 50 hours before needing maintenance.
All these durations depend a lot on the specific generator and how well you maintain it.
How long can a generator run continuously?
A portable gas generator can run continuously for around 8 to 18 hours before letting it rest to refuel.
A portable propane generator with a big fuel tank can run for up to 24 to 50 hours. At this point, you want to cut it off for maintenance tasks like an oil change.
According to Petro, standby generators can run continuously for up to 500 hours. However, running your equipment this long without rest is typically not recommended.
How long can a standby generator run continuously?
According to Petro, a standby generator can run continuously for up to 500 hours.
At the same time, they also note running your generator for this long is typically not recommended.
This run duration also assumes that you have a big propane tank or natural gas as a fuel source.
It is possible that your standby generator will “only” run for shorter amounts of time due to refueling requirements.
How long can a portable gas generator run continuously?
A portable gas generator can run continuously for around 8 to 18 hours due to fuel tank limits.
After this time period, you will simply have to give your equipment a break to refuel.
And even if you have a dual fuel or tri fuel generator, you want to give your machine rest after 24 to 50 hours for maintenance and cool down.
How long can a diesel generator run continuously?
A standby diesel generator can run continuously for around 10 to 50 hours before you have to refuel the tank.
Similarly, a smaller portable diesel generator will only run continuously for around 5 to 30 hours.
After this, you will have to refuel the equipment and potentially apply maintenance like an oil change.
How long to run a generator for maintenance?
According to CAT, you should run a generator for about 10 to 20 minutes a month for maintenance.
That being said, many generator brands only recommend changing the oil about every 50 hours of use or 6 months of use as maintenance.
Whether you actually run the machine or not is often not specified.
When in doubt about the best maintenance practices, you want to check your manual or customer support.
FAQ
Can you run a generator 24 hours a day?
No, you can not run a generator 24 hours a day indefinitely. Your generator will need to rest after a certain amount of time.
Is it safe to run a generator all day?
No, it is not always safe to run a generator all day every day. That being said, there are still many standby generators that can safely run a few days at a time.
A portable generator can also often temporarily run all day as long as you give it rest after these 24 hours and have enough fuel.
