As soon as you finish reading this article, you’ll know how long can you run a generator continuously! Let’s get started.
One of the most important aspects when it comes to generators is the amount of fuel they use over time.
Your average generator will use approximately 0.5 gallons per hour while running at a steady pace, and it will take around 12 hours to use up 1 gallon of gasoline.
It will also use about 0.6 gallons when it runs on high-speed for 15 minutes and then idles for 10 minutes or so.
These are the factors to consider before you calculate:
- Size
- Brand
- Fuel Source
How long can you run a generator continuously?

If you want to find out how long your generator will run based on the size of the unit and amount of fuel it contains, here’s a handy formula:
Hours = (Fuel Capacity – Gallons) / 0.5
For example, if you have a 10-hp, 2.5-gallon generator with dual power sources, it will last for (2.5 – 2) / 0.5 which equals to 8 hours as long as you run at low speed for most of the time.
Petrol Powered Generators
Petrol-powered generators are among the most common ones in the market. We’re going to look at two distinct types:

- four-stroke engines
- two-stroke engines
The difference between the two is in how they operate. Four-stroke engines have an intake, compression, combustion, and exhaust stroke while two-stroke engines have an intake, power, and exhaust stroke.
This difference does not change how much power they can produce but it does affect their efficiency.
You can run these type of generator for around 6-12 hours continuously.
Diesel Standby Generators
Diesel generators are very similar to petrol generators. However, they use either diesel oil or gas oil as fuel.

To keep the generator running for a long time, you need to ensure that the oil supply is sufficient enough without it overheating and damaging the unit.
Also, make sure that there’s access to fresh water for the generator and that you have plenty of it on hand; otherwise, your generator will not work at all.
The average diesel generator will run for about 3-10 hours before it needs a refill.
Portable generator with Gasoline
Portable generators are the most common generator types. This is because they can be portable and are often assembled through a car battery to power anything from a CFL to a flat-screen TV.
Modern ones are lighter in weight, especially those made for campers, and are more like backup power banks.

In order to run for as long as possible however, you have to remember that you have to recharge your phone or tablet at least once every two weeks; otherwise, it will not work on standby mode.
Medium-sized generators can run for 2-5 hours before they need refilling with gas or oil. This is much longer than petrol and diesel ones but less than the bigger units that operate at their maximum capacity continuously.
Portable generator with Propane
Propane generators are very similar to petrol and diesel ones. However, they use propane as fuel instead of gasoline.
The fuel consumption is also different: for every hour of constant operation, they can run for up to 15 hours while modern models can sustain the same performance for 20-30 hours.

Portable generators are more like backup power banks since they are much smaller in size compared to the bigger units that operate at their full capacity continuously. They can run up to 2 hours before recharging is required for longer periods of time.
Conclusion
We’ve taken a look at how long can you run a generator continuously. You’ve learned about the different fuel types that are used, and you may have even been able to figure out how long your own generator can run for.
No matter which generator you use, it is extremely important to take good care of it so that it will run smoothly for as long as possible. This means making sure that there’s enough fuel in the tank, and cleaning it periodically if necessary.
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