Does Motor Oil Expire?

Does motor oil go bad? When does engine oil (or motor oil) expire? Here's the only guide you'll ever need about motor oil storage and expiration.

Producers of motor oil label their products with a shelf life of around five years. But is that number justified? Does oil expire and lose its chemical properties?

Motor oil does expire, eventually. You’ll usually find a recommended shelf life of about five years.

Contact the car manufacturer or oil producer if you need help finding the date.

Failing that, use common sense. If you’ve had oil for a decade, it’s probably useless.

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Different Types Of Oil

Service Manual

Motor oil keeps internal car parts lubricated and cool. This prevents engine seizure and ensures your car runs smoothly.

You must use the correct type of oil as stated in your owner’s manual.

The three types of motor oil mentioned below all last for different lengths of time.

Conventional Oil

5W 20 vs 5W 30 Motor Oil

Conventional oil is for older vehicles. It doesn’t last as long as synthetic oil.

It results in a quicker build-up of sludge and carbon, affecting fuel consumption. Therefore, if you drive an older car, you should regularly top it up. This means the oil on your shelves doesn’t go off.

Your owner’s manual will tell you exactly when to change your oil.

Conventional oil is more affected by your storage environment than other types. Temperature and humidity will wreak havoc on it and could render it unusable.

Of course, you must always store oil in a safe spot.

Fully Synthetic Oil

Synthetic Motor Oil

Fully synthetic oils are used in most modern cars and last longer than others.

It’s not affected by temperature as badly as conventional oil. The oil won’t go rancid so quickly.

With fully synthetic oil, you’re looking at an excellent shelf life of at least five years. However, it will still expire eventually (contrary to popular internet myth).

You’ll only need to get new oil for your car every 6,000 to 16,000 miles – again, this is detailed in your owner’s manual.

Synthetic Blend Oil

A synthetic blend oil will last longer than synthetics but not as long as conventional.

As the name states, this oil is a blend of conventional and synthetic. Motor oil producers aim to give you the best of both worlds, all at a reasonable price.

Does Motor Oil Have A Shelf Life?

Motor Oil Shelf Life

Sadly, oil isn’t a resource that lasts forever.

When it comes to determining when oil has gone off, it gets tricky. Not only will the oil in storage canisters go bad, but the old oil in the engine can also get old.

It’s not just the oil companies forcing you to buy more!

Look out for the following things.

Check The Expiry Date On The Bottle

Motor Oil On Shelves

Your bottle or canister will have an expiry date printed on it.

Usually, this date is around five years from the purchase date for conventional oil.

Synthetic oils will last the longest. They’ll last for five to eight years.

However, this only applies to unopened bottles stored as described on the packaging. As soon as the bottle is opened, it would be best to use it within a year.

Color Of The Oil

Is Engine Or Motor Oil Flammable

It’s worth checking the oil in your engine.

You’re good to go if the oil has a fresh amber color.

However, you’ll want to consider changing the oil if the oil is clearly dirty and black.

Air, dirt, or moisture often cause the engine oil to turn color and go bad. It’s essential for your car’s health to get an oil change right away, as rancid oil will reduce your engine’s power and longevity.

Consistency

Motor Oil Closeup

The pouring process should be easy and smooth when you refill your motor oil. If a slimy, clumpy liquid comes from your bottle, your oil’s gone bad.

Dispose of it (see below) and buy some new oil. You’ll immediately notice how it pours much nicer.

What You Can Do

Get Your Motor Oil Changed

Change Engine Oil Soon

Check your owner’s manual and service booklet. This details exactly when you need an oil change.

You’ll also see the light flash up on your car when it’s time for an oil change. Don’t ignore it!

When the time comes, take your car to a mechanic and get the oil changed. Have the service booklet stamped, too.

Check Oil Levels Regularly

Car Service

If you regularly check your oil level, you’ll know when it’s time for a top-up. This way, the motor oil on your shelf won’t age unnecessarily.

Checking the oil level every month is a reasonable period. You’ll notice any problems sooner that way.

  1. Ensure your car is parked on a level surface.
  2. Next, take the dipstick out and wipe off any oil at the end. Insert it all the way again.
  3. Now remove the dipstick and check where the top level of the oil is located.
  4. This level must be between the minimum and maximum markers on the dipstick.

Should your car be new, double-check your manual. You might have an electronic oil monitor.

Recommended Storage

Motor Oil On A Shelf

All car oils have recommended storage instructions written on a label on the bottle. However, as a rule of thumb, you’ll increase the life expectancy of motor oil by following these tips:

  • Store unopened bottles in a dry, dust-free environment, far from moisture.
  • Keep it away from fire hazards.

Make sure you still follow the storage instructions! As motor oil can catch fire, be aware of its considerable danger.

If you follow these rules, you’ll get the most out of your motor oil and ensure it doesn’t go off before the expiry date comes around.

Has Your Motor Oil Expired? Use Waste Collection Sites And Recycling

Recycle

You’ve just found out your motor oil is expired. What should you do next?

First, never chuck expired motor oil in your garbage bin or pour it down a drain.

Not only will you harm the environment, but it’s also illegal.

The old oil must be disposed of correctly at a waste collection site. In the US, you can find these here.

Motor oil suppliers and chains often will also take back expired oil as part of green initiatives.

Also, you can call your local gas station to see if they will take expired motor oil. Check in beforehand, as some gas stations charge a small fee for the collection.

Make sure to find out what kind of contamination level they expect. Most states insist on proper disposal of contaminated oil.

Conclusion: How Long Does Motor Oil Last?

car engine oil fill port open

Here’s the long and short of it: read your owner’s manual and do precisely what it tells you.

By these standards, you’ll need an oil change at least every year or every X,000 miles. Thus, the overall life of motor oil isn’t too relevant.

If you bought motor oil ten years ago, it’s probably not worth using. If you’ve only had it on the shelf for a couple of years, it should be fine (provided it’s been sealed).

An open bottle of engine oil shouldn’t be used after a year.

If in doubt, get rid of the oil you’ve had standing around for years in your cellar. Your car will thank you, and you’ll always have a smooth-running engine at peak performance.

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Benjamin Kitchen

Ben is an automotive author from England. With experience in a fast-fit garage, he's an IMI-qualified light vehicle technician. He aims to help drivers worldwide with common automotive problems. You’ll often find him working with his 1.2 Vauxhall Corsa – it may have a tiny engine, but in eight years it's never once let him down!

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