Which is more important: Oil or Filter?

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RDY4WAR

RDY4WAR

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This was a discussion with a couple friends. We pretty much knew the answers, but weren't sure the extent. I figured I'd bring that discussion here.

Can a superior oil's benefits be diminished by an inferior filter?

Can an inferior oil be improved with the use of a superior filter?

Discuss!
 
What's more important: blood or liver?
smile.gif


But when it comes to oil/filter, I'd say oil is more important primarily because your engine will run without a filter, but will not run (for very long) without oil.
 
Originally Posted by RDY4WAR
This was a discussion with a couple friends. We pretty much knew the answers, but weren't sure the extent. I figured I'd bring that discussion here.

Can a superior oil's benefits be diminished by an inferior filter?

Can an inferior oil be improved with the use of a superior filter?

Discuss!


Assuming only using full flow filters,

Yes, poor performing bypass valve, poor efficiency, low capacity can limit OCIs regardless of oil.
Why use an inferior oil, except for economic reasons. A filter is designed to filter, it will not improve an inferior oil, it might reduce the larger damaging wear metals caused by the inferior oil.
 
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Originally Posted by RDY4WAR
This was a discussion with a couple friends. We pretty much knew the answers, but weren't sure the extent. I figured I'd bring that discussion here.

Can a superior oil's benefits be diminished by an inferior filter?

No, but its condition will worsen more quickly if you use a filter that does not meet spec than with a filter that does. How much is unclear, however.

Originally Posted by RDY4WAR

Can an inferior oil be improved with the use of a superior filter?

No.

A filter can never 'improve' new motor oil which already meets spec. It can only slow the buildup of contaminants.


... The most important oil filter a car can have is a good air filter.
 
Noria a lubricant specialist site dealing with big $$$$$ machinery lubrication + some vehicle information how VERY important a good filter is!! better oil is a choice depending on application with extreme heat + or cold requiring higher quality real synthetic base oils! big rigs all use multiple filters one normal + one bypass for extreme fine filtering. of course with cases instead of quarts of oil extending its life is cost effective for sure!
 
Well - there has to be a filter with modern engines, but it's probably far more important to have oil flowing. I mean - isn't that why there's a bypass on most filters?

Might also depend on the car. I look at the Honda 1.7L I-4 in my wife's car where Honda specs a 30-40 micron filter changed every other OCI. And that's with at least API SJ motor oil. Obviously the filter isn't super efficient, the oil itself is pretty basic, yet there are those driving them forever where the engine seemingly will outlast the rest of the vehicle.

I think this is Canadian spec and it looks a bit different than my wife's car (where's the tach?) but he's got over 400k km on it.
 
Just to note... I'm not talking about an absence of oil or anything like that. I'm referring to such as a conventional oil matched with a high efficiency filter like a Fram Ultra and a PAO/POE oil matched with a low efficiency filter.

What if... you had a 5.5 quart sump for both of these scenarios. What if you were to use a bigger oil pan and taller filter to increase the oil capacity to 8 quarts. How much of a difference in OCI would that make for the cheaper conventional oil?
 
(a) Microgreen claims their filters are so effective, that if you change the filter every 6,000 miles and top off, you can go 30,000 mile OCI's.

I don't think you want to do that, but I wouldn't go (b) 30,000 miles changing the oil every 6,000 and staying with the same filter.

Given a choice, which would you go with: a or b?
 
Every study done shows that cleaner oil results in less wear in machinery. The oil filter is the only thing that cleans the oil. Do the math.

Of course oil is more important to keep an engine going, so the question is a bit nonsensical to start with. The oil filter is one of 3 factors that helps keep engine wear down, so why ignore it more than the oil or the air filter.
 
While I wouldn't want to run a car without an oil filter, I would have to say the oil is the most important. Your lawn mower / snowblower or really old VW engine that don't have filters would agree.
wink.gif
 
The oil is what really matters. Good filtration is very important as well, but the filter is there to maintain the oil. A historical note: my 1969 VW (1st car, owned in 79-80) didn't even have an oil filter. The engine had an internal oil "strainer" but that was it. Obviously, a car very different from what we're driving now (mostly), but still, those card lasted year after year this way.

To reiterate, proper filtration is critical to the overall health of modern cars. Still, one could probably go filterless (rigging that however...), change oil every couple hundred miles, and do just fine. Just food for thought -- please don't anyone actually try this idea!
 
Z06's point is well taken -- it's a pretty theoretical question. In practical terms, I insist upon using both top quality oil and filters.
 
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Oil.

How long did your family briggs and stratton mower run without an oil filter?

Filter isn't far down the list....air first, then oil.


UD
 
Originally Posted by Burt
(a) Microgreen claims their filters are so effective, that if you change the filter every 6,000 miles and top off, you can go 30,000 mile OCI's.

I don't think you want to do that, but I wouldn't go (b) 30,000 miles changing the oil every 6,000 and staying with the same filter.

Given a choice, which would you go with: a or b?


I may be mistaken but I thought Microgreen recommended changing the filter every 10K (not 6K)?
If I had to choose, I'd prefer a good synthetic with a regular filter over a conventional oil and an Ultra filter....
 
Originally Posted by y_p_w
I think this is Canadian spec and it looks a bit different than my wife's car (where's the tach?) but he's got over 400k km on it.

My 1985 Corolla has 439,000 km (273,000 mi) and I'm still trying to break in the engine. Lol. No oil consumption yet (I replaced the valve-stem oil seals though). The transmission is also clockwork. It looks better than that Civic, too, except for paint issues.

[Linked Image]


I don't think the type of oil and filter makes much a difference if you have a well-built engine. The more important thing is shorter OCIs, especially with conventional oil. With conventional oil, I never exceeded 3000 miles (well, except once or twice). If you exceed the oil's longevity, you can have bearing and ring corrosion.

Also, usually the fuel and emissions systems cause the most problems and you need to maintain them well.
 
Originally Posted by benjy
Noria a lubricant specialist site dealing with big $$$$$ machinery lubrication + some vehicle information how VERY important a good filter is!! better oil is a choice depending on application with extreme heat + or cold requiring higher quality real synthetic base oils! big rigs all use multiple filters one normal + one bypass for extreme fine filtering. of course with cases instead of quarts of oil extending its life is cost effective for sure!


Not all big rigs use multiple filters. The truck I drive at work with a Cat C-15 550HP engine only has one oil filter. Its a big filter, but just one. The other trucks at my work have the Cummins ISX 565HP engines and they only have one oil filter as well.
 
Both are important but to pick most important one : Oil.

If you have City Star or worse in the sump your engine is in for a rough time; plus numerous engines have run just fine with only a mesh screen as an oil filter.
 
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