Most efficient filter for Impreza

[horse123]

So I've been reading that the K&N filters let in some dirt particles other filters wouldn't, and that it raises silicon. Wondering if going with a realllllly good oil filter would offset some of this?

I'm too stubborn to trash the $55 filter I just bought less than a year ago, plus in the mountains I need every gram of air I can get through the intake. I've been running the compatible Wix filter because it's one of the only ones with the proper bypass pressure rating. However, I see so many people running other filters with significantly lower bypass PSI, even a couple people running 5w30 when the car specs 0w-20.

What's the best thing to do in this case, keep my wix that probably has fairly poor efficiency, or buy something else that can help filter out some of the silicon so it's not continuously circulating in the oil?

 

[JHZR2]

How do you know the particle size of the "silicon" in your oil?

 

[horse123]

I don't... that's why I said best possible filter.

 

[901Memphis]

Silicon getting into the oil is going to be smaller than the filter can trap i am betting. The first line of defense is making sure you have a quality oem style paper AIR filter to prevent it from getting in in the first place.

As far as the oil filter goes, forget the OEM bypass settings and get a Fram Ultra. Fram builds oem filters for all these manufactures, they know what settings the bypass needs to be relative to the media differential pressure. The ultra flows crazy gallons per minute, so it's the least likely filter to go into bypass during hard runs anyways, as well as any of the other microglass media filters including Royal Purple or Amsoil.

 

[wemay]

I used K&N for every one of the 175K miles i owned my Evo VIII with no elevated Si numbers on any of the 6 UOA done. The highest reading was 9ppm. Since the early 90s, almost every car owned has had one installed. If you believe there is reason for concern, use Fram Ultra, Royal Purple or Mobil1 oil filter.

 

[05LGTLtd]

Ditch the K&N air filter and get a quality disposable. Contaminats and oil fouling of the MAF is just not worth it.

If looking for oil filter, Fram Ultra is easy to locate. Microgreen is a bit more exotic, but might be worth looking into as well.

 

[horse123]

Originally Posted By: 05LGTLtd
Ditch the K&N air filter and get a quality disposable. Contaminats and oil fouling of the MAF is just not worth it.


The intake is cleaner than an operating room behind the filter. Oil only comes from idiots that overoil their filter after cleaning it. No factory oiled k&n has ever left any oil film in an intake.

 

[901Memphis]

This thread is confusing. The OP is talking about K&N oil filters letting dirt through but I think he's confused on what he read about K&N air filters in the other sub forum.

The K&N air filters do have some issues filtering fine dust compared to oem paper style filters.

The K&N oil filters are somewhat low efficiency wise about 85% @20 microns but that's still higher than Toyota oem or other oem filters which aren't high efficiency usually. Obviously Fram Ultras are better at 99%+ at 20 microns and 80% @ 5 microns, so the Fram Ultra filters about the same at 5 micron particles as the K&N oil filter does at 20 microns which is a pretty big upgrade on the filtering curve if you are using the Ultra

 

[horse123]

Originally Posted By: 901Memphis
This thread is confusing. The OP is talking about K&N oil filters letting dirt through but I think he's confused on what he read about K&N air filters in the other sub forum.




Actually no I'm not. I'm talking about the K&N air filter I have installed.

 

[ZeeOSix]

Originally Posted By: horse123
What's the best thing to do in this case, keep my wix that probably has fairly poor efficiency, or buy something else that can help filter out some of the silicon so it's not continuously circulating in the oil?


If it's the regular WIX (not the WIX XP), then the efficiency is rated at 95% @ 20 microns which isn't bad at all.

 

[901Memphis]

Originally Posted By: horse123
Originally Posted By: 901Memphis
This thread is confusing. The OP is talking about K&N oil filters letting dirt through but I think he's confused on what he read about K&N air filters in the other sub forum.




Actually no I'm not. I'm talking about the K&N air filter I have installed.


Well you posted under the OIL FILTER subforum, there is an AIR Filter subforum.

 

[05LGTLtd]

Not sure which Impreza you have. Unless your at a stage3 WRX, the stock airbox flows well enough, with a media filter, which it was designed for. At Stage3, it's time for a new intake to match flow. If this is a NA impreza, you got no worries at all.

Have you run a VOA to determine if you are actually seeing higher contaminants to be concerned about?

 

[901Memphis]

Looks like AC DELCO makes some filters for certain years, I would try that

 

[Unicorn01]

Originally Posted By: 901Memphis
Originally Posted By: horse123
Originally Posted By: 901Memphis
This thread is confusing. The OP is talking about K&N oil filters letting dirt through but I think he's confused on what he read about K&N air filters in the other sub forum.




Actually no I'm not. I'm talking about the K&N air filter I have installed.


Well you posted under the OIL FILTER subforum, there is an AIR Filter subforum.


Yes, he's asking if a better oil filter will make up for the increase in particles the air filter will let pass.

 

[dlundblad]

Originally Posted By: 901Memphis
Originally Posted By: horse123
Originally Posted By: 901Memphis
This thread is confusing. The OP is talking about K&N oil filters letting dirt through but I think he's confused on what he read about K&N air filters in the other sub forum.




Actually no I'm not. I'm talking about the K&N air filter I have installed.


Well you posted under the OIL FILTER subforum, there is an AIR Filter subforum.


Dang man..

He was just curious if a high efficiency oil filter would be a good addition to offset the low efficiency air filter.

 

[901Memphis]

Originally Posted By: dlundblad
Originally Posted By: 901Memphis
Originally Posted By: horse123
Originally Posted By: 901Memphis
This thread is confusing. The OP is talking about K&N oil filters letting dirt through but I think he's confused on what he read about K&N air filters in the other sub forum.




Actually no I'm not. I'm talking about the K&N air filter I have installed.


Well you posted under the OIL FILTER subforum, there is an AIR Filter subforum.


Dang man..

He was just curious if a high efficiency oil filter would be a good addition to offset the low efficiency air filter.


I addressed that in my first response like he intended then re-read it and got confused.

I do not believe a better oil filter can make up for the small dirt particles let in by the air filter. The silica in the air is very small. I would also have to say it can never hurt to have a high efficiency filter if OEM flow requirements are met such as with micro glass units that are quality.