How Long Does Oil Last In A Car Not Driven?

How Long Does Oil Last In A Car Not Driven?

Oil is the lifeblood of your car engine, reducing friction, carrying away heat, and performing many other essential functions even when the vehicle isn’t regularly driven. However, despite a popular belief, the fact is that infrequently driven cars need oil changes as regularly as daily-driven vehicles.

When motor oil sits in an engine over long periods, it can degrade, reducing its lubricating properties and potentially causing engine damage.

This guide explores how long oil lasts in a car that’s not driven often and why regular oil changes are still crucial.

The Shelf-Life of Engine Oil Inside a Car

The shelf life of engine oil inside a car that’s not often driven can vary significantly depending on several factors. Generally, manufacturers suggest changing oil every 3,000 to 7,500 miles but for a car that is not driven frequently, this mileage can extend over a long period.

As a rule of thumb, industry experts recommend changing the oil in a car that’s not often driven at least once a year or every 5,000 miles, whichever comes first. It’s important to note that oil doesn’t degrade just by sitting. Instead, the engine components degrade the oil over time.

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Factors Influencing Oil Shelf-Life

The lifespan of oil in a car that is not driven regularly is influenced by several factors.

  • Type of Oil: The type of oil used in the engine plays a crucial role in its lifespan. For example, synthetic oil generally last longer than conventional oil due to their superior resistance to thermal degradation and oxidation.
  • Car’s Age and Condition: Older cars or those with mechanical issues may contaminate the oil faster, reducing its lifespan.
  • Climate: Extreme temperatures can affect the oil’s consistency. In cold weather, oil can become too thick, while too much heat can make it overly thin, leading to inadequate lubrication.
  • Car’s Storage Condition: If the car is stored in a covered and dry place, the modern engine oils may last longer, while exposure to humidity or condensation can lead to its early degradation.

Risks of Leaving Oil Untouched for Too Long

Ignoring oil changes in a car that is not driven often can lead to several complications.

  • Deposits Formation: Oil naturally breaks down over time, forming deposits. When the car is driven, these deposits can clog critical engine parts leading to inefficient operation or even failure.
  • Oil Oxidation: Over an extended period, oxygen can react with the oil, leading to oxidation. This process can create sludge and increase the oil’s viscosity, reducing its effectiveness as a lubricant.
  • Acid Formation: Condensation in the oil can lead to acid formation, which can corrode the engine parts.
  • Reduced Lubrication: As oil ages, its lubricating properties can deteriorate, leading to increased friction among engine parts. This increased friction can result in rapid wear and potential engine damage.

Therefore, it’s always advisable to follow the manufacturer’s guidelines for oil change frequency, even if the vehicle is not often driven.

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Risks of Leaving Oil Untouched for Too Long

While your car may not be accumulating miles, the oil inside can still degrade and potentially put your car’s engine itself at risk. The damaging impacts of leaving oil untouched in your car for too long can be significant.

Firstly, oil degradation is a primary concern for cars left idle. Over time, oil can oxidize and thicken, losing its capability to flow smoothly throughout the engine. The outcome of this process can be an inefficiently lubricated engine, leading to a higher risk of engine component damage.

Secondly, oil left unused in the engine can lead to the build-up of sludge. Sludge is a thick, dark substance that can clog up the engine’s oil pathways, lowering the overall performance of the engine and leading to potential engine failure if not addressed promptly.

Thirdly, unused oil sitting in old or damaged engines can cause oil leakage. Overfilled oil reservoirs or deteriorated seals can lead to this issue. Oil leaks can harm other vehicle parts and cause environmental damage.

Finally, leaving old oil in your engine can lead to reduced lubrication of moving parts. This decrease in lubrication further accelerates engine wear and tear and could lead to engine seizure if unchecked.

Oil Change Recommendations For Cars Not Frequently Driven

While the rule of thumb has traditionally been an oil change every 3,000 miles or every three months, this may not apply to cars that are not frequently driven. However, even in this case, oil changes shouldn’t be ignored.

Experts recommend changing your oil at least once a year or every 5,000 miles for cars that are not frequently driven. Still, it’s always a great idea to consult your car vehicle owner’s manual for the manufacturer’s recommendations.

When monitoring your oil level, pay attention to a few key indicators that suggest your oil may need changing:

  • Color: Fresh oil has a transparent light brown color. Over time, as it becomes dirty and less effective, it darkens. If your oil is a dark, thick color, it’s likely time for a change.
  • Smell: Oil that’s in good condition should not have a strong odor. If you notice an intense, burnt smell, this could indicate that your oil is old and needs replacing.
  • Texture: Fresh oil has a smooth texture. If you rub some between your fingers and it feels gritty, this may signal that your oil is contaminated and needs to be replaced.

Remember, the cheapest way to maintain your car’s health in the long run is to keep up with regular maintenance tasks, such as oil changes—even when your car isn’t being driven frequently.

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Final Words — How Long Does Car Oil Last?

In conclusion, while your car may be parked more than it’s driven, it’s essential to remember that the oil still needs regular attention. Leaving engine oil unchanged, especially in a car that isn’t frequently driven, can lead to several risks such as engine sludge, reduced lubrication, oil leaks, and even potential engine failure.

The shelf life of the oil inside your car varies and depends on factors like the type of oil, the age and condition of your car, and the environment where your car is stored. Although synthetic oils can often last longer than conventional oil brands, no oil, synthetic or conventional, is immune to the effects of time combined with the elements and engine contaminants.

Monitor your oil regularly and ensure it’s replaced at least once a year or every 5,000 miles, whichever comes first. Pay attention to the color, smell, and texture of your oil as it can give you a fair idea about when you need to replace it. Even though they’re sitting idle, keep proper maintenance of your vehicles to ensure they run smoothly when you do hit the road.


How long does oil last in a car engine?

The lifespan of the oil inside your car can vary, but as a rule of thumb, you should change it at least once a year or every 5,000 miles, whichever comes first.

How long until a car runs out of oil?

A car doesn’t typically “run out” of oil. Instead, the oil degrades over time and gets contaminated. When this happens, it’s essential to replace the oil.

Can car oil last 2 years?

It’s not recommended to let your car oil last 2 years without a change. Even if you’re not driving the car much, the oil can still degrade and get contaminated.

Does engine oil go bad?

Yes, over time, engine oil breaks down and becomes less effective at lubricating the engine and absorbing heat.

Can I use 10 year old engine oil?

It’s not recommended to use engine oil that’s been sitting unused for 10 years. Over time, oil can degrade and lose its effectiveness.

How frequently should I change engine oil?

For a car that’s not driven often, change the oil at least once a year or every 5,000 miles, whichever comes first. For regularly driven cars, refer to your vehicle’s manual for the manufacturer’s recommendations.


Wesley Kolbe

At the helm of AET Systems, Wesley Kolbe merges tradition with innovation to provide top-quality lubricants and unmatched service, ensuring every client's machinery runs at its best.