8

This is one of those myths that doesn't go away.

Many vehicles can accept larger oil filters, which provides more filtration media and higher oil capacities.

Are their any tangible performance benefits to doing this?

I used an oversized filter in my old Jeep LJ for one reason only: it accepts slightly less than 6 quarts of oil. With the larger filter I could safely put in exactly 6 quarts.

10 Answers 10

8

I've had to use slightly smaller oil filter in order to accommodate a larger downpipe on my car. Nothing bad (that can be traced back to that change) has happened as a result since the change (probably 15 years ago now). Oil pressure and volume are still right where they should be, but in theory the change could impact that. You need the appropriate pressure and volume for your engine. Volume needs to be sufficient, pressure should fall between a min/max range (too much can be as bad as too little).

6

As long as the specific part is applicated to your vehicle then it is fine. As Brian, mentioned there is a lot more to oil filters than diameter and height. The wrong filter (even if it is the same size) can starve an engine of oil or switch the filter over to bypass mode.

Not worth the risk to get a possible marginal better oil life.

2

When motor manufacturers put together a new model of vehicle, or introduce a new engine they are extensively tested under all conditions. When you look at your oil filter you can sleep easy that it has been tested over thousands of cars and thousands of miles and has come out of it smelling of roses. A larger, smaller, or otherwise differant oil filter will offer no real benefits or gains. It will not prolong oil changes, it will not make the car go faster or use less fuel. But it will open the prospect of a failure into your cars lubrication system, how ever unlikely. Use the manufacturers oil filter, or an OEM match, and change the oil and filter according to its maintenance schedule using the recommended oil.

2

Many OEMs offer several filters of similar construction, so no compromise need be made on quality or basic performance.

All things being equal, a larger filter has two key benefits - 1) more oil capacity in the system, which helps extend useful life, and keep temperatures down, 2) more filter area means greater dirt holding capacity and therefore greater filtered flow for longer, before filter media saturation and bypass valve actuation.

The only thing that matters beyond these factors is fitment, burst strength, and most importantly bypass opening pressure value. Fitment is straight forward, burst strength is rarely much of a concern, and bypass opening pressure is often published, or can be determined by dissecting a filter.

Generally however, the OE filter design should be more than adequate for the average user, and this is more a matter for people interested in maximizing every detail of their vehicle performance.

2

There is no need for improved filtration, except when vehicle operates in dusty environments, such as my Jeep does. In a dusty environment improved air filter and oil filter filtration is helpful. So to that end I prefer a high filtration oil filter that filters 10 micron particles (most oil filters only filter 20 or 21 Micron particles).

I like Mobil One oil filters because they filter particles as small as 10 microns. I don't use Mobil One oil, but I do use their filters for this reason. They also flow more/easier than standard paper oil filters. They offer finer filtration AND more flow in OEM size filter, and even more flow in a large oversize filter.

The higher flow and larger the filter, the more time it spends filtering, and the less time it spends in bypass mode. Oil pressure is unaffected (if you choose a filter that has same bypass pressure as OEM filter).

Mobil One filters are already both high filtration and high flow in stock OEM size. The larger oversize M1 filter I use is massive over kill, but cost same as OEM size.

A larger oil filter needs to have the same specs (as OEM size filter) for threads, diameter, bypass valve pressure. Those specs are published at each oil filter manufacturer's website.

No matter what size oil filter you buy, you should always get one with an ANTI-DRAINBACK VALVE because this keeps oil in the filter when engine is turned off. This keeps filter full of oil, which reduces the time it takes for oil pressure to come up at cold start.

The anti-drainback valve should be standard on all filters, but is not. Cheap filters lack an anti-drainback valve. Quality filters (of any brand) have an anti-drainback valve.

So if a larger filter has an anti-drainback valve, being larger won't affect the time it takes oil pressure to come up at cold start.

With any filter, ESPECIALLY A LARGER FILTER, it is important to prime a new oil filter before installing it. Priming the filter prevents (or reduces) dry start after changing the oil.

Here's how to prime a new oil filter before installing it:

If filter mounts thread side up, do this to prime it: Fill up the threaded center hole with oil. Let it sit for a few minutes for filtration material to soak up oil. The oil level in the filter will drop a lot as it soaks up oil. Fill the filter a second time, then install it.

If filter mounts laying on its side, do this to prime it: Fill up the threaded center hole with oil. Let it sit for a few minutes for filtration material to soak up oil. The oil level in the filter will drop a lot as it soaks up oil. Fill the filter up halfway this time time, then install it. It won't make a mess if you quickly tip it into place and spin in on quickly.

The above is how my cousin primes oil filters. He's a mechanic. He primes all oil filters before installing them. However, he exceptionally thorough.

I doubt most mechanics bother to prime oil filters. If a larger than stock filter isn't primed, it's harmful because (if unprimed) it increases the time it takes oil pressure to come up when the car is started after an oil change. That causes a longer lasting dry start than you'd get with an unprimed OEM size filter.

With an OEM size filter, priming it (at time of installation) is very beneficial, but not required. With a substantially oversized filter (like I use) priming the filter is a necessity.

Charley

1

As with most things. It's more complicated then everyone makes it seem. The safe answer is stick to OEM. But Car enthusiasts can't deny advancements in technology offer possibly more flexibility and improvement. My answer is this.

A Synthetic Media Filter with advanced/stronger components like they are making now with silicone anti-drainback valves,outside coatings, better materials, will naturally be able to offer a smaller size for the same performance as a older/originally intended filter. They are putting smaller filters on everything now, the oil is better, the filters are better.

You can always lower your viscosities within the OEM range, a lower cold viscosity/winter is always a smart and desirable option, if your vehicle was originally intended for 10W-30. It is without question, an upgrade to go to 0W-30. Where it gets more complicated is changing the normal operating viscosity, the high number. Old-school fuckwits will preach going to 0W-40 or above etc. This is operating on the principle of that if you go a higher operating viscosity you have more flexibility for long term intervals and "more protection". This is a uneducated and false lie. You should never go higher then the OEM. You can experiment with lower, but never higher. Advancements in technology allow lower weight viscosities to offer the same amount of protection as at lower viscosity. If your car is 10 years or older. I would safely say you could lower the high weight by 5W. If it is 20 years or older. I would say lower 10W. Modern oil is ridiculous. I say all this because it factors into your original question

For power/mpg I would decrease filter size by half an inch for every 5W decrease in viscosity if you can find a compatible filter.

For Longevity/Protection I would stick to Original size /Half an inch increase from original specs per 10 years.

I switched from 0W-20, to the new 0W-16. I decreased my engine filter size half an inch. My hot viscosity is now lower = less pressure. Smaller size filter = more pressure, balances out for better performance and my car has a less rough idle.

How long do you plain your drain intervals is another question.

If you do the ridiculous 20-25k Intervals. Drive safely and gradually, but a bigger long term filter, is not the answer as long your not hot dogging it or towing constantly, it is the smartest when it comes to cost efficiency. A bigger filter is only necessary when you are CONSTANTLY putting higher pressures then normal.

Regardless. Vehicles are made one way from factory.

If your going to increase your oil filter size. You need to increase pressure somewhere else, otherwise as the people above me have said, you'll run into issues, newer oils might offer the same if not protection then older ones, but this doesn't change pressure. Find the middle ground.

I personally think increasing the filter size doesn't pose many benefits.

You would get a better effect by doing filter only oil changes at the right size.

20'000 -25'000 oils 10'000 right size or smaller oil filter.

Older car? Pressures probably starting to drop anyway. A smaller filter will help slightly.

0

You would definitely want that larger filter in an application where the vehicle is being used for heavy construction.Most cars won't see any measurable benefit by going to a larger filter.The size of filter that can be used is probably limited by the engine design.

0

P.S. - For anyone who cares about their engine and filtration, the air filter is the first line of defense. The oil filter is the last line of defense.

Stock (or stock equivalent) air filters do the best job of filtering. Aftermarket upgrade filters boasting high flow get that extra flow by not filtering as well. i.e. - aftermarket high flow air filters let a lot of dirt into your engine.

I learned that the hard way with my Jeep. I went back to stock air filter after a fancy aftermarket filter let a lot of dust and dirt into my engine.

Stock air filters work well at keeping contaminants out of your engine, but some still get in there. The oil filter's job is to clean up the contaminants that got past the air filter, as well as clean up combustion contaminants.

Charley

1
  • While what you say may be true, do you have any references or proof that aftermarket air filters do not do the job they portray to do? Without it, this answer is more opinion than it is anything else. On StackExchange we try to back up anything we say here with reference to add credibility to what we are saying. Sep 5, 2015 at 16:03
0

I experienced a low oil pressure in my 4.8 litre gm one day after sitting for 10 days while getting body work. Had demos full synthetic oil changed with filter just before going in to shop. Pressure was normally 40 psi. But now was 20 psi at idle , 30 psi at 60 mph. Gm shop did a engine psi test and found the same. They installed a larger corvette filter. All back to 40 psi normal oil pressure at a idle,

-1

There are not benefits either way really. I personally prefer OE type, however you shouldn't encounter any issues!

1
  • You may end up slightly increasing the longevity of the oil. Although I don't know by how much or if it's even worth it. Nov 21, 2013 at 8:54

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .