Why do the auto manufacturers (or at least the ones I encounter) say, in their vehicle owner's manuals, to change oil at, let's say, 7.5K miles and not change the filter until some ludricrous interval like, for example, 15K? Why would you want to put new oil thru an old, "contaminated" filter as they apparently recommend?
One interval for oil changes and another for filter changes?
- Thread starter Ganton
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Ease of maintenance and lower maintenance costs. Clearly they believe the filter won't clog in a single interval (open for debate), not an unreasonably assumption for most engines, and it's therefore good for two cycles.
But I'm with you -- I can't bear the thought of "dumping" a half-quart of old oil out of a used filter back into an engine following an oil change. Although I use PureOnes, Kragen Auto (a Southwest chain) recently had STP filters on sale for $1.99. My point being, for those of us who keep an eye out for sales, there would NEVER be an excuse to avoid a filter change if one can do so for an additional $1.99, unless you have one of those very few rides in which the filter's almost impossible to reach.
But I'm with you -- I can't bear the thought of "dumping" a half-quart of old oil out of a used filter back into an engine following an oil change. Although I use PureOnes, Kragen Auto (a Southwest chain) recently had STP filters on sale for $1.99. My point being, for those of us who keep an eye out for sales, there would NEVER be an excuse to avoid a filter change if one can do so for an additional $1.99, unless you have one of those very few rides in which the filter's almost impossible to reach.
Well, the other side is that in general filters are useless and can easily go 15,000 miles and still not have captured anything anyway. How about cutting one open at 7500 and one at 15,000, will there be any difference? I have gone 6 and 12,000 and done this. No difference, no difference in the UOA either.
Kestas
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One thing that strikes me odd is that generally people shudder at the thought of leaving a quart of dirty engine oil during an oil change, but aren't bothered by changing only 30% of the transmission fluid during a transmission fluid change.
I guess it depends on the make. Neither my Ford truck nor Chevy car mention a different interval for oil and filter.
"Well, the other side is that in general filters are useless and can easily go 15,000 miles and still not have captured anything anyway."
When looking at the photos in the following link, one might actually think they're seeing metal particles and shavings imbedded deep into the filter pleats of a cut-open filter. But this is not the case -- it's strictly an optical illusion. Why? Because filters are "useless," and therefore trapped metal particles like these could never have happened...
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=6;t=001422
When looking at the photos in the following link, one might actually think they're seeing metal particles and shavings imbedded deep into the filter pleats of a cut-open filter. But this is not the case -- it's strictly an optical illusion. Why? Because filters are "useless," and therefore trapped metal particles like these could never have happened...
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=6;t=001422
...and some of us want to change the filter at HALF the mileage of the oil, if they're running LONG oil-change intervals.
I agree to some extent with Spector, that filters are designed to catch the 'BIG' pieces--those larger than about 30 microns or 0.0012"--so changing them MORE often than oil makes NO sense to me. But they do filter some pieces.
I change the filter with the oil, every 6 months or about 10,000 miles, which is half of Porsche's recommendation.
I agree to some extent with Spector, that filters are designed to catch the 'BIG' pieces--those larger than about 30 microns or 0.0012"--so changing them MORE often than oil makes NO sense to me. But they do filter some pieces.
I change the filter with the oil, every 6 months or about 10,000 miles, which is half of Porsche's recommendation.
On the face of it, that does sound odd, but the transmission doesn't have the same contamination issues a crankcase does, especially condensation combining with blow-by gasses to make acids, etc, so as long as you change the ATF more often than the manual recommends, it shouldn't be a problem. I'd be willing to bet most dealers don't do a whole-system flush when they change ATF at the "recommended" intervals, either...
Its a matter of cnvenience. Dropping the pan is a pain in the ars. But don't forget you don't have combustion products in tranny oil..so its really not quite the same. Most Nissans get over 50% on a drain. So instantly you decrease your dirt and contaminents by more than 50%. Also takes the additive up by 50% and brings up the vicosity. I have done 5 drains and fills in the first 3 years and probably will shoot for a drain every 10-15K.
i have done this. my filter at 7500 miles looked like new, just stained dark but there was nothing in the filter, no "gunk". my filter interval is now 15,000 miles, and the next time i change filters i a going to cut it open and take pictures for you all.
you know what else is odd, is that alot of people here have no problems running their dirty oil out to 10 or 15 thousand mile change interval, but yet wont let half a quart of this dirty oil "taint" their new oil? what is up with that...
I wonder if a oversized filter should be changed even more rarely than that.
At only $3 each for a good quality Motorcraft, Napa or Purolator, it seems like very cheap insurance to change the filter with the oil.
I thought is was the other way around. Example, 10K OCI with filter changes at 5K. I'm going to run my PureOne filter to 10K with the oil (Delvac 1 5W40) and not even thing twice about it.
I would be money that the intermediate point oil filter changes used in some "extended drain" scenarios is really all about getting .5 to 1.0 quart of fresh oil into the engine to do a partial change out.
I always put a new filter on when I do the oil change. The truth is that I've been doing it that way for over 20 years now and am getting set in my ways
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John
I always put a new filter on when I do the oil change. The truth is that I've been doing it that way for over 20 years now and am getting set in my ways
John
filters have their function..do you really think that you can see a micron level particles with naked eye...please!
****! The filters on my cars barely hold a cup...
"I agree to some extent with Spector, that filters are designed to catch the 'BIG' pieces--those larger than about 30 microns or 0.0012"--so changing them MORE often than oil makes NO sense to me. But they do filter some pieces."
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Mercruiser's recent filter study showed PureOne (the finest filtering of the bunch) to have pores down to the 11 micron range. Since the landmark AC-Delco/Detroit Diesel SAE Test #881825 determined that most engine wear is caused by particles in the 2-22 micron range, filtering by the "premium" filters down near the single-digit numbers (1-9 microns) can be reasonably assumed to substantially reduce engine wear. Not a "useless appendage" by a long shot.
"I wonder if a oversized filter should be changed even more rarely than that." A good point, Pacem. The Bosch #3312 has 81 sq in of media, and the PureOne #24458 about 175 sq in, both for Honda applications. It seems reasonable that one could leave these filters on for greatly differing intervals.
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Mercruiser's recent filter study showed PureOne (the finest filtering of the bunch) to have pores down to the 11 micron range. Since the landmark AC-Delco/Detroit Diesel SAE Test #881825 determined that most engine wear is caused by particles in the 2-22 micron range, filtering by the "premium" filters down near the single-digit numbers (1-9 microns) can be reasonably assumed to substantially reduce engine wear. Not a "useless appendage" by a long shot.
"I wonder if a oversized filter should be changed even more rarely than that." A good point, Pacem. The Bosch #3312 has 81 sq in of media, and the PureOne #24458 about 175 sq in, both for Honda applications. It seems reasonable that one could leave these filters on for greatly differing intervals.
I disagree that an oil filter is a useless appendage. Visual inspection of a cut open filter is not a good indicator.
The 6 month filter change is a good rule of thumb. Like an air filter, an oil filter will become more efficient with age up to a point, then you risk physical breakdown and it should be replaced.
I don't belive a visual inspection tells you much about how much a filter can hold, etc. or the condition of the media.
The 6 month filter change is a good rule of thumb. Like an air filter, an oil filter will become more efficient with age up to a point, then you risk physical breakdown and it should be replaced.
I don't belive a visual inspection tells you much about how much a filter can hold, etc. or the condition of the media.
Not long at all.
I would do neither, filter and oil changed at the same time. What's so wrong with that?
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