How Long Does Diesel Fuel Last – Storing Tips

How Long Does Diesel Fuel Last – Storing Tips

Diesel fuel is the common term for petroleum oil, which is used in the diesel engines. Nowadays, this fuel is basically a very important component of our daily life. Also, this fuel is useful to start and run a diesel generator during a power outage. We just need to spread awareness to the society of the importance of diesel and to know how long does diesel fuel last with useful storing tips.

Some basic properties that are used to characterize diesel fuel include Cetene number, Fuel volatility, Fuel viscosity, Fuel cold behavior, Sulfur content. Maybe the shelf life of diesel is shorter than you think. There are a few reasons who is responsible for the decrease in diesel fuel life. The oxidation process of diesel fuel is very fast. Because diesel fuel is carbon-based petrochemical, so they make sediments and gums, that the major reason for clog fuel beginning.

Without diesel fuel additives and its fast oxidation process, diesel fuel can go bad in less than 30 days. Because of the oxidation process, diesel fuel creates deposits and that can danger for fuel injectors, fuel lines, and other system components.

Today the diesel sold nationwide is ultra-low sulfur. This type of diesel fuel contains low sulfur and also emission is lower. However, if the sulfur quantity is low in diesel fuel that means the life of diesel fuel not as much as long. But if we store diesel fuel at an optimal temperature of between 70 to 85-degrees Fahrenheit, we can increase diesel life between 6 to 12 months before it begins to degrade.

If we manage the temperature kept below 70-degree Fahrenheit, the life of diesel can slightly longer. But mostly we can not store diesel for more than 18 months.

Following are the useful storing tips regarding how long does diesel fuel last

Avoid the effects of oxidation

Oxidation effects are natural things and processes in fuel, The oxidative degradation of diesel was caused by the peroxidation chain mechanism, which started with a hydrogen-abstraction reaction in the methylene group (−CH2−) from polyunsaturated fatty acids. This leads to the formation of hydroperoxides. In turn, the fuel properties of the diesel became degraded.

We can’t 100% prevent diesel from oxidation, but we can minimize or avoid its harmful effects. The following are some suggested solutions to prevent oxidation.

Keep the storage tank cool

The key factor to avoid oxidation is a cool tank. Diesel fuel exposed to high temperatures accelerates the formation of solid particulates, which could end up clogging the fuel filter. A warm environment combined with moisture can also cause microbial growth in the tank. The ideal temperature is 20°F but we need to observe,  tank temperature is not more than 85°F.

We can balance the temperature of the storage tank by providing a roof or we can use an underground diesel tank. We can also use some special type of enclosure to avoid the hot sun rays as well as reduce exposure to water sources.

Fuel treatment

The treatment of fuel is helpful to maintain the quality of fuel. We can stabilize diesel fuel and prevent a chemical breakdown. You need to treat fuel but treat it right. There is no need to use a special type of chemical, which claims to prevent microbially. Gasoline and diesel are two different petrochemicals and they need some specific technology. Treatment of diesel is different from other petrochemicals so you need to require specific technology.

Save from water

The most primary thing to include in storing tips to extend the life of diesel fuel is to save it from secondary water. Secondary water is one of the challenging issues for diesel. Because new blends of diesel contain more water in it. If this water is not separated from the fuel, it will be injected into the system and into the fuel injector and it will be a big cause to damage part of the diesel engine

For example, a new common rail fuel system works on high pressure, up to 40,000 PSI. If one small drop of water injected in this high-pressure system, it can blow the tip-off, which is an expensive part of the engine.

To minimize this water issue we can keep diesel tank full, which is helpful to reduce the amount of condensation space in the diesel tank, thus reducing the amount of water. We can also use diesel fuel treatments which is helpful to demulsify or separate water from the fuel. Almost all the diesel engines are equipped with the fuel Water Separator filter.

Short-term and long-term management to prevent diesel from water

Short-term management

  • By using biocides– You can use biocides, it will help to prevent the growth of bacteria and fungus, which is present because of the water-diesel interface. Once they present in the diesel tank the growth of microbial is very high.
  • By using fuel treatment that separates water from the fuel– In the present time, all the diesel tanks are most likely equipped with a fuel water separator filter, which is helpful to prevent water.
  • Top off the tank- If the diesel tank is full, then the condensation chance is very low.
  • Check the tank after rain– You will maintain the tank structure integrity by checking it regularly, and you need to remove pooled water on top of the tank.

Long-term management

  • Check the tank in a fixed time of period– You make sure, maintenance schedule to periodically or a fixed time of period. You need to check the water inside the tank and remove the water which has pooled at the bottom of the tank.
  • Empty and clean the tank– Cleaning of the diesel tank will help to maintain not only the life of the diesel but the life of the tank also.
  • Cover the tank– You can prevent rainwater and from damage by cover your diesel storage tank.
  • Use underground storage tank– The initial cost of an underground storage tank is maybe more, but the long term cost is always less. The underground storage tank is safer, temperatures cooler and the quality of fuel will last longer.

Microbial growth

Diesel fuel contains a 7% amount of biodiesel, this biodiesel amount is good for our environment but this is not good for the organization that store fuel. Biodiesel is hygroscopic because of this reason it holds and attracts more water as compared to petrochemical diesel. The amount of water is not good for diesel fuel.

Water presentation in diesel is one main cause for the growth of diesel bug, the formation of gums and resins which can stick to the side of fuel tanks and injectors. It can also make a layer of sediments inside the tank. You need clear your diesel tank, every fixed time of period to avoid microbial growth in the tank.

Tips to prevent microbial growth

  • Keep water away from diesel fuel– If the amount of water is nill in diesel, the conditions for microbial growth are nil. Water is the main reason for microbial growth.
  • By using biocides– Biocides used to prevent the growth of microbial and kill if any exists. Biocides are useful when you contain diesel in high volume.
  • Prevent biofilm– Diesel water interface is the main reason for growing biofilm. It is a very thick, sludge-like mass. The presentation of biofilm can reduce the effectiveness of biocides and encourage the re-infection of microbial growth after fuel treatment. If the biofilm present before biocide treatment, you need to clean the diesel tank mechanically. Then only you will get the benefits of biocide.

Fuel industry advice for diesel fuel

The fuel industry suggests that if you keep diesel fuel clean and store in a cool and dry place, you can store diesel 6 months to 1 year without significant fuel degradation.

You can store fuel up to 1 year by following certain conditions.

  • First, you should purchase clean and dry fuel from a reliable supplier.
  • You need to improve the cetane number of diesel and provide detergents to clean the fuel system.
  • Just use additives, biocides, and stabilizers to improve the lubricity of diesel.
  • And at last, the fuel should be regularly be tested and maintained. If necessary you need to polish all portable generator filters.

If the above conditions are not matching, you should not store diesel for the long term, otherwise, Hydrolysis, Microbial growth, oxidation can come to the fuel.

So, “how long does diesel fuel last ”, well the answer depends on the proper maintenance and treatment of fuel. If you can do this, you can store and use diesel for a long time.

Storing tips for diesel fuel

In the previous chapter, we have discussed “how long does diesel fuel last”, that basically depends upon, how we store and give treatment to the fuel. Now we will take a look at “how to store diesel for longer”.

How to prolonge diesel life?

  • You need to ensure diesel is not in contact with any surfaces, which contain any metal like zinc or copper. Just use a metal deactivator additive to avoid this metal component issue.
  • You have to establish a regular fuel maintenance program to ensure that the presence of water and dirt is removed from storage. This will also help to remove any fungus if present.
  • You have to check, water should be drained from the storage tank weekly or monthly as per storage tank condition.
  • To reduce the space for water, you need to keep your storage tank full. Maximum time water comes from condensation as the tank breathes, the rate of water is dependent on the local climate and it will be higher in a humid area.
  • The storage tank should have a well-defined bottom point, where water will collect and drain. Like the cone bottom.
  • You need to clean your storage tank at least once, every 8 to 10 years.
  • Establish a good design filtering system to avoid small particles which are present in diesel.
  • The filter should check and replace, in a fixed time of period or when they need it.
  • Ensure that the supply of fuel comes from reliable suppliers.
  • If you purchase fuel in huge amount, always purchase in the winter session. This will ensure that fuel has no wax problem whatever session it will use.
  • Ensure to establish a monitoring program whereby the sample is taken check the density and other features of diesel regularly.
  • If possible then use your stored fuel as soon as possible and replaced your storage tank with fresh diesel.


Diesel and other petrochemicals are equivalent to lifeblood for our machine. We need to ensure the diesel we have used for our machine is clean and quality is good. Choosing the wrong one will impact how your engine will work. The life of diesel is short but we can increase it by good treatment. It will also beneficial for our machine.

We hope, this article will help you to better understand diesel fuel and how long you can store it by following useful storing tips.

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