Can I Use The Same Oil Filter Twice? (And Other Oil Filter Questions Answered)

In theory, your filter has a simple job: capture wear-causing contaminants and hold them in the filter media so they don’t run amok inside your engine.

But lots of factors can throw a wrench into this plan, which can raise filtration questions. 

Here’s what we’ll cover:

  • Can I use the same filter twice?
  • How long do filters last?
  • I forgot to change my filter when I changed oil. Is it too late?
  • Should I pre-fill the filter before installing?
  • Should I use a conventional or synthetic filter?
  • What’s inside an oil filter?
  • Can I use synthetic oil with a conventional filter? Or vice versa?
  • Can I use the same filter twice?

    The filter is designed to capture contaminants and hold them within the filter media. Over time, the media fills with dirt particles, agglomerated soot, metal particles and other junk. If the filter plugs, the pressure differential will open the bypass valve, which allows oil to bypass the filter, preventing oil starvation. Sure, dirty oil is preferable to no oil, but it’s not a long-term plan you can trust.

    A new filter is far less expensive than a new engine. Don’t cheap-out – replace the filter with every oil change.

    How long do filters last?

    It depends on filter quality and your driving conditions.

    A low-quality, cheap conventional filter doesn’t offer the capacity of a filter using synthetic media, meaning it fills with contaminants faster and requires more frequent changes. Plus, if you drive in dusty, dirty conditions, your engine is exposed to increased levels of airborne dirt particles that can enter the engine, especially if you haven’t changed the air filter in awhile or there’s a leak in the intake system.

    Some modern direct-fuel-injection vehicles experience elevated fuel dilution, which also takes a toll on the filtration system. In diesel engines, soot particles can agglomerate into larger contaminants and lodge in the filter. This all adds up to more contaminants and more stress on the filter.

    Follow the filter manufacturer’s service guidelines. If none are given, go with what’s recommended in your vehicle owner’s manual.

    AMSOIL Oil Filter

    Shop AMSOIL Oil Filters

    I forgot to change my filter when I changed oil. Is it too late?

    No. Just change the filter as normal.

    After the new filter is installed, run the engine for a couple minutes, then shut it off and allow several minutes for the oil to settle in the sump. Check the oil level and top-off as needed to make-up for the oil removed with the old filter.

    Should I pre-fill the filter before installing?

    The Internet is full of pre-fillers and anti-pre-fillers, all of whom seem able to reference a high-mileage conversion van or pickup they’ve serviced for decades either pre-filling or never pre-filling the filter.

    Some filter manufacturers say pre-filling the filter isn’t necessary. But remember – they make filters, not engines. There’s a reason engine manufacturers recommend 0W-XX or 5W-XX motor oils, and it’s so the oil flows readily at startup when it’s cold and the engine doesn’t go without vital lubrication while it builds oil pressure.

    To help ensure the engine doesn’t start dry, we recommend you pre-fill the filter if you can.

    Horizontally oriented filters can pose a problem, but even they can be pre-filled with some oil. I typically pour a little oil into the filter and tip it sideways and check the oil inside. If there’s room for more before it begins to spill out of the opening in the filter, I add a little more oil before installing the filter.

    Oil filter
    When you remove the filter, make sure the o-ring comes with it.

    Should I use a conventional or synthetic filter?

    Use a filter made with synthetic media for best protection. Synthetic oil filters offer the following benefits:

    • Increased efficiency – Efficiency describes the filter’s ability to capture contaminants. You can usually find a filter’s efficiency rating on the package or the manufacturer’s website. It’s reported as a percentage followed by a micron rating (e.g. “99 percent at 20 microns,” which is the efficiency of AMSOIL Oil Filters). It refers to the percentage of contaminants 20 microns and larger the filter traps in industry-standard (ASTM D4548-12) testing. The higher the percentage, the better.
    • Increased capacity – Capacity refers to the amount of contaminants a filter can hold while still remaining effective. While there’s no industry-standard capacity rating, similar to the efficiency rating noted above, full synthetic media offers greater capacity than conventional media. The smaller fibers in synthetic media allow more room for contaminants to lodge without restricting oil flow.
    • Improved durability – Hot oil slowly degrades the resins that hold some filter media together. Extreme temperatures also degrade the anti-drain valve and baseplate gasket. Use a filter with reinforcement on the media, such as a wire backing, to withstand increased heat and longer drain intervals. Look for an anti-drain valve made of silicone for maximum durability. This ensures the oil stays in the filter after the engine is shut off, preventing dry starts the next day.

    What’s inside an oil filter?

    Most spin-on filters contain the following:

    • Filter media – the heart and soul of the filter. It’s where contaminants go to die. Once they lodge inside the filter media, they can’t circulate throughout your engine and cause wear.
    • Anti-drain valve – prevents oil from draining out of the filter when you shut-off the engine, ensuring immediate oil pressure at startup.
    • Gasket – technically it’s on the outside of the filter, but the gasket that creates a seal against the engine block is critical to preventing oil leaks.
    Oil filter inside

    Can I use synthetic oil with a conventional filter? Or vice versa?

    Yes, it’s perfectly safe to use either type of filter with either type of oil.

    If you practice extended drain intervals using synthetic oil, however, a conventional oil filter may not offer the required service life, meaning you’ll have to change it in the middle of the oil drain interval, which is inconvenient.

    That’s why AMSOIL Oil Filters are constructed to last up to 25,000 miles between changes, coinciding with the 25,000-mile drain interval of Signature Series Synthetic Motor Oil. AMSOIL Oil Filters designated with product code EA15K offer 15,000-mile change intervals.

    Find an AMSOIL Oil Filter for Your Vehicle

    Updated: Originally published Oct. 16, 2017

    Comments

    1. I’ve been changing oil since I was around 13, had to change my Dad’s oil when I was a kid. I’ve never filled the oil filter with oil before putting it on. I’m 58 now. Actually never heard of it till recently, I don’t think it is a bad idea, but I agree with Scott above theirs enough residue in the motor to protect it for a few seconds which is all it would take to be protected before circulating again at full capacity. Having said that maybe I’ll start putting a little in the filter!

    2. I have a 67 E jag that uses fabric type filters . Have used them in Jags since 1961 without a oil problem. Of course no extended oil changes. I am wondering If these particular filters are better than most natural fiber ones. Also does Amsoil offer a recommendation as to oil for XKE 4.2 1967. As well as trans and differential oil.

    3. You can go 20K miles if you use the best oil filter money can buy- FRAM Ultra Synthetic. The ONLY filter that has the capacity to go 20k with no time restrictions. 99.9% [email protected] microns and 8.99 at retail. There is nothing better.

      1. Have you ever opened a fram filter and actually seen the inferior parts and design that it’s made with??

    4. But if you pre-fill should you pre-fill from the filter’s large centre hole or from one of the perimeter inlet holes so you can be sure all the oil that goes in is filtered and no contaminates enter the system? There are those strongly recommending the latter see http://beamalarm.com/Documents/prefilling_oil_filter_instructions.html and http://www.widman.biz/uploads/Corvair_oil.pdf (point 23 page 20) and https://www.youtube.com/watch?v=P6MLDH0zTp And whatever side your pre-fill on does it move to the other side or is the visible drop in oil level inside the filter simply the media soaking it up? Is new oil contaminate free?

      1. Hi Ross,

        Fill the filter whichever way is easiest for you. New oil from the original package should not be contaminated, so pouring it into the center hole of the filter is OK. As you pour oil into the center hole, you will fill the volume and the media will begin soaking it up until saturation. Oil will naturally flow through the media, helping fill the entire canister. Many filters have anti-drainback valves, making it hard to fill the filter without using the center hole.

        If you have concerns about this, use an oil you can trust to be manufactured properly. I can’t speak for the other oil companies, but we take pride in the manufacturing of our products, and each and every gallon we produce is filtered prior to going into the bottle, providing you exceptional engine protection.

        Thanks for reading.

    5. Mobil one offers 20000 mile filters for my vehicle to go with their annual
      Protection product you only off the 15K filter for my 2015 Nissan Versa note. Are you going to offer a longer lasting inh filter?

      1. Hi James,

        We offer an AMSOIL Ea15K Oil Filter for your Nissan Versa, which provides a 15,000-mile service interval.

        If you elect to use the Mobil 1 Extended Performance filter for its recommended 20,000-mile service interval, just make sure you understand the fine print regarding Mobil’s filter warranty:

        “This warranty does not cover any filter that: a) has been subject to misuse, neglect, negligence, accident or casualty; b) has been improperly installed; c) has been installed into an engine which is not referenced as a conforming to the purchaser’s vehicle requirements; or d) has remained in service beyond the original equipment recommended change interval. This limited warranty does not include engine condition due to: normal wear; abnormal operation; negligence; abuse; or damage from casualty, shipment or accident.”

        Pay special attention to line “d” above. Also, check out Mobil’s FAQ page, where they tell you to “Please follow the recommendations in your owner’s manual while your car is under warranty.”

        Your Nissan Versa Note carries a 5,000-mile/six month oil-change recommendation. So, if you follow the recommendation in your owner’s manual, as Mobil instructs, your 20,000-mile oil filter essentially becomes a 5,000-mile oil filter.

        In contrast, if you use an AMSOIL Ea15K Oil Filter in your Nissan, the AMSOIL Limited Warranty will cover you in the unlikely event of a filter-related problem regardless of the oil-change recommendation given in your owner’s manual. That means you can confidently use the filter for its full 15,000-mile service interval and sleep well at night.

        Plus, AMSOIL Ea15K Oil Filters provide better efficiency (98.7% at 20 microns, compared to 99% at 30 microns for the Mobil 1 Extended Performance filter).

        Thanks for reading.

    6. Only time an engine starts dry is after a rebuild. Bearings lubed with white whipped oil from a tube. If you think an engine goes dry during an oil change let it,sit as long as you like. Remove the pan and change a couple bearings. I’m a 40 year mechanic and have tried letting it drip dry. Can’t be done. Doesn’t take long at all for oil pressure to fill the filter plus many vehicles have a filter mounted sideways. In my opinion pre filling an oil filter is just another one of those things because people have done it that way for years.

    7. People like what they like, I make a project out of an oil change….try this on your next one…I cut off the spout part of one of the bottles and use the bottom 3/4 of the container to drain the oil out of the other bottlles…I get almost two shot glasses worth of oil after letting the empty bottles hang up side down in the bottle I cut the spout off from. I usually let them drip there for a day….This oil is sticky and it sticks to the inside of the bottle very well….I know every so often the industry say”we recommend” this now but tried and true always works…I picked up a few filters this weekend and the lack of types of brands to choose from is getting slimmer….I stay with OEM but l noticed that the extended range filters are in the $12 dollar range….I guess if you hate changing oil then that would be a better price option but if you are a 2 times a year and under 12.000 miles like me then I’ll have to get what I can when I can…The shelves I seen this weekend were either one sided with one of off name brands or high prices big namers….Oil needs to be changed and you need to be on top of your driving habits to balance the costs….less is best but no one answer covers everyone…

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