Updated at: 08-07-2022 - By: Lucas

Engine oil makes the engines of cars and other motor vehicles run more smoothly by reducing friction.

When you put it inside of them, it acts as a lubricant and helps reduce mechanical wear.

But if it’s been sitting on a shelf in your garage for years or if you haven’t started your engine in a long time, you may be wondering if it’s still good (if that even is such a thing).

If you leave engine oil out for too long, it could go bad. If you don’t open the bottle, they should last about 5 years. The shelf life goes down quite a bit after it has been opened. If you don’t leave an open bottle in the sun, it might last for six months.

Most engine oils work by using different kinds of hydrocarbons. Hydrocarbon chains are sensitive to changes in light and temperature.

So, if you put them in the sun, they will break down. Warming them up also makes them less useful for longer.

Does Engine Oil Have an Expiration?

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Additives are used in modern production methods to change how the final product works. Some of them want to make the oil last longer by making the bonds stronger.

Technically, oil can last forever as long as it is stored in the right way.

But few of us can store it in the best place. So, after a couple of years on the shelf, it will lose some of its effectiveness.

Pay attention to the date on the bottle when you put it away. That should tell you when you can expect it to run out.

But if you store the oil well, you can make it last longer than its expiration date.

Make sure it’s not in a place where the temperature will change a lot.

You should also try to keep it somewhere that isn’t in the sun. Oxidation is one of the most important things that affects how long oil will last.

In general, synthetic oil will last longer than conventional oil.

It hasn’t been worked on as much, so it falls apart more quickly. They’ve also never had anything added to them.

Depending on how good it is, a bottle of engine oil that hasn’t been opened can last between 2 and 5 years. If you want to use the bottle later, keep the lid on it so it doesn’t break down too quickly.

After the bottle has been opened, it has a much shorter life. A bottle of engine oil that has been opened will last less than a year.

Make sure you’ve used it all up before a year passes. If not, the rest will spoil.

Even with the top on, oxygen can get into the bottle if you open it. The hydrocarbon bonds in the oil react with the oxygen in the air.

This makes the oil less thick over time, which makes it useless.

Putting oil in the engine should make it last for a while.

When you drive the car, the oil doesn’t get stuck. But don’t leave the car sitting for more than a month without draining the oil. If the engine doesn’t move the oil around enough, it can start to go bad.

Does Synthetic Oil Expire?

There are a few ways in which synthetic oil is different from regular oil. These changes improve the oil’s qualities and make it last longer. As part of the process of making oil, engineers add things to it.

Some of its properties are changed by additives to make it work better in the engine.

Some of them work by stopping oxygen from oxidising the oil before it does so. Other additives help keep the oil’s thickness in check so it doesn’t get too thin.

That doesn’t mean, though, that synthetic oil will last forever. If everything stays the same, you can expect it to last longer than regular oil. But if you look at the bottle, it still has an expiration date.

The length of its hydrocarbon chains is another reason why it will last longer. When synthetic oil is refined, most of the shorter chains are taken out.

So, after refinement, the only ones left are the long ones.

Long chains of hydrocarbons are stronger and less likely to oxidise.

How to Know When Your Engine Oil Is Expired?

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What happens when the oil’s date of use-by has passed? There are a few ways you can tell if the oil in your engine is still good.

The easiest way to tell is to look at the date on the bottle that says “best by.”

Most of the time, you can find the date at the bottom. If it hasn’t been opened, conventional oil can stay stable for about 5 years.

Synthetic oil can stay good for up to eight years if it’s never opened. If you don’t know how long yours should last, look at the date on the bottle.

The colour of the oil is another easy way to tell if it has gone bad.

If you look at your oil in bright light, it should have a yellow colour. See what colour your oil is by looking at the dipstick.

The colour of expire oil is much darker. So, if your oil is dark, it needs to be changed. As the oxidation process goes on, the colour gets darker.

When it’s first taken out of the bottle, oil looks almost clear. You shouldn’t be able to see things moving around inside.

Look at yours in bright light to see if there’s anything you can see. If you can see through the oil, you should change it.

Viscosity is a measure of how thick and easy to move an oil is.

Fresh oil should flow easily and not stick together. When oil gets old, it gets thicker and turns into sludge.

If your oil looks like muck, you should change it.

What Happens If You Use Expired Motor Oil

If you’re not careful, using old oil could hurt the parts inside the engine. Oil reduces the friction that happens when the parts of the engine move.

Old oil doesn’t reduce friction as well and can cause the engine to get too hot.

In fact, if the engine doesn’t have enough oil, you could blow the whole thing.

If the oil in the engine is old, you might be able to drive a short distance. But you shouldn’t go too far without changing the oil.

Having fresh oil also keeps the engine from wearing out too quickly. So, if you want your car to last longer, you should always use good oil.

How to Extend the Shelf Life of Engine Oil

You can store your engine oil in the right way to make sure it lasts as long as possible.

When the temperature changes, the bonds will break down more quickly than usual.

So, keep oil somewhere where the temperature stays the same.

Don’t leave it in bright light either. Hydrocarbon bonds weaken over time when exposed to ultraviolet light. If you left oil out in the sun, it would go bad a lot faster.

Never open a bottle of engine oil if you’re not going to use it right away. As soon as you open the bottle, it has a much shorter shelf life.

Try to put the bottle somewhere cool and out of the sun. It should also have low humidity to stop moisture from building up.

If you do all of these things, your oil should last for a while. If you store it well, you could still use synthetic oil that has been sitting on the shelf for 8 years.