The Great Filter Debate

[Duffman]

Here is a guys site that I had bookmarked from quite a while ago. He has cut apart a lot of filters but I am not sure how up to date it is.

Engine Oil Filters

[Sandy]

Originally Posted by Duffman

Here is a guys site that I had bookmarked from quite a while ago. He has cut apart a lot of filters but I am not sure how up to date it is.

Engine Oil Filters

It's tagged at the bottom as 1999.
not that current,
but good info anyway.

[dremd]

Just wanted to make sure that everybody had been to Bob is the oil guy forums.
Bob Is The Oil Guy - Powered by Motor Oil

Specifically Bob Is The Oil Guy - Powered by Motor Oil

Oh; and since I'm getting K&N filter adds in this thread, Filtration Testing for Amsoil, K&N, Napa, Jackson Racing, Baldwin, and Mazda air filters on a Miata Not the worst; but close.

[flydude1221]

Bob is The Oil Guy is a WEALTH of info on this subject.

Carquest Blue Brand Filters (Wix) on my VX and any other vehicles I happen to procure, as the guys at BITOG have said time and time again Wix makes the best cheap filter, Purolator being the best at more $$ but much cheaper than an AMSOIL filter.

Another piece of the puzzle to consider is the Bypass valve which on some filters is complete junk and can cause the filter to bypass oil before it is even close to being clogged.

[Bror Jace]

Yes, BITOG

For another $4-6 per year, I can treat my car to a much better oil filter. This is something that more reliably keeps bits of metal out of critical areas and is less likely to give me a dry start on a cold morning.

They are well worth it.

Also, for what is some of the shoddiest workmanship in an automotive product, Fram filters are NOT the cheapest. Supertech (made by Chmpion Labs) are better. Purolator are better still but Wix, Baldwin, Hastings and a few of the OEMs are my favorites.

For those of you skimping on oil changes, the coefficient of friction of the oil goes up as contaminants accumulate and the additive package becomes depleted. As friction goes up, heat and drag increases ... reducing efficiency. The pennies you save will cost you over the road.

I'm with The Mullet. Change your oil and use good supplies when you do.

[tasdrouille]

Originally Posted by Bror Jace

For those of you skimping on oil changes, the coefficient of friction of the oil goes up as contaminants accumulate and the additive package becomes depleted. As friction goes up, heat and drag increases ... reducing efficiency. The pennies you save will cost you over the road.

I'm with The Mullet. Change your oil and use good supplies when you do.

Sorry to steer the thread in an other direction, but I'd just like to mention a way to know if you need to change your oil (appart from an oil analysis).

All you need is an oil pressure gauge and oil temp gauge.

When you change your oil with fresh oil, record the pressure at idle for a given temperature (fully warmed engine).

Later in time, as long as the pressure at the same rpm and temperature remains the same you don't need to change your oil.

As Bror mentionned, as the oil age, accumulate dirt and contaminants and additives get depleted, the viscosity of the oil will change. You can detect the change of viscosity by monitoring the pressure of the oil under the same flow (rpm) and temperature.

[some_other_dave]

Yeek! I wouldn't let it go that far. In my view, when the oil can't keep up its viscosity, it is really well and truly dead dead dead! And probably should have been changed a while ago.

I also don't feel that a combination of oil temp and pressure readings off of (fallible) gauges is an accurate enough method to assess the condition of the oil. And getting it wrong can be quite expensive...

Then again, I come from the air-cooled world, and we tend to be really (over?) zealous about changing our oil.

-soD

[flydude1221]

I wonder how the GM oil change monitor system decides when to tell you it is time to change? Maybe they just detect the pressure and temp to a given table of values ?

[trebuchet03]

Originally Posted by Bror Jace

For those of you skimping on oil changes, the coefficient of friction of the oil goes up as contaminants accumulate and the additive package becomes depleted. As friction goes up, heat and drag increases ... reducing efficiency. The pennies you save will cost you over the road.

Yes, friction goes up as contaminates accumulate and additive packages deplete... But to say my long oil change interval = accumulated bits and depleted additive packages is a fallacy.

Every oil change, I send a sample to a lab for testing. I can tell you, with certainty, my contaminates are low*, insolubles are low (filter is filtering ), viscosity is within acceptable limits, and TBN has always been above 6.0

*except for copper - 2000 VW 2.0 engine had their piston rings installed upside down from the factory (piston ring mfr started stamping their label on the bottom rather than the top as they did prior: as a result, a chamfer isn't where it's supposed to be) - so occasionally copper wear is a little higher than it should be, but not by much.

My best tank to date was on oil with over 9K miles (that's conventional oil too ). Yes, that's anecdotal - I'm just throwing that out there

[trebuchet03]

Originally Posted by flydude1221

I wonder how the GM oil change monitor system decides when to tell you it is time to change? Maybe they just detect the pressure and temp to a given table of values ?

Not entirely sure how GM does it - a friend once explained to me that it's based on starts/stops, miles, etc. etc. and thrown into an algorithm. If that's the case, you'll probably have to trust that GM got it right AND that they're not short selling you (outside of a reasonable safety factor).

But BMW, from whatever article it was that I read, uses "electrical properties" (resistance?) of oil which change as the oil wears out.

Not sure how effective it is....