Synthetic oil change

Maybe Mobil may want to use it as a discriminator for their EP full synthetic oil line and hasn't bothered to secure GF5 for lesser oils? I dunno. There's a lot of marketing in how a company positions their products.

I'm pretty sure I've seen other GF-5 mineral oils, just can't recall. I think the only oil that's synthetic only right now is 0W- weights, so there should be some GF5 mineral oils out there.

 

filter By pass valve should not open unless , filter is 100% clogged. If bypass on the filter opens any other time then its faulty.
There are bypass valves in engine and they are preset at different pressure levels. First one sits right after the oil pump and before filter. Thats the one that will open when your engine is cold or you hitting RPMS.

 

True that... but the effect is the same. The filter is bypassed.

 

I imagine with me changing my oil so frequently (every 3 months) that using a GF-4 oil wouldn't be an issue, correct?

Sorry to hijack a little, but this may come in useful for the OP should he change to conventional.

Fink

 

So his point is still valid, the oil filter would still be bypassed under certain conditions just by means of the engine, not the flap in the filter itself.

 

To put it in perspective: the 3 month/3K mile OCI was the 'standard' with API SE, ILSAC GF... oh... I dunno, maybe even before there WAS an ILSAC standard. So yes, I have to believe changing GF4 oil at 3 months is safe!

I believe the time limit part of the oil change interval is mainly intended for protection against corrosion. The additive package (which protects against corrosion) will break down with lots of contaminants in the oil which build up if you don't drive very often to flash them off so they suggest changing it.

 

My only concern would be the high temps here in Florida - but it sounds like I'll be just fine. Thanks for the help!

OP,

I hope this helps make you feel more comfortable if you do end up going with conventional after your warranty is up.

Fink

 

look into getting the bypass filter system and some good oil from AMSOIL.com, you can run 10-20k miles with that.

get a good air filter as some have already stated

 

Sort off. The first bypass sends oil back to oil pan. Its sized to specific volume, and spring that it uses is preset to open at specific pressure. So only reduces pressure/volume beyond maximum spec'ed forcing "working"pressure volume through filter. You can not go beyond working pressure because first bypass valve can open to maximum possible (in case chewing gum is stuck in the oil line towards the filter or something like that ).

Oil line to filter is what 1/4 in diameter? so as long as there is 1/4 inch by 1/4 inch of clean filter medium, filter will let the oil flow. Surface of the filter is few thousand times bigger then oil line so it can support a lot of oil volume at low pressure. Otherwise all those paper filled Oil filters would be imploding in the instant. I believe bypass valve opens when pressure inside the filter goes beyond 4 psi .
In essence bypass oil valve in the filter does not open unless filter is filled with junk or bypass valve is faulty and opens at almost 0 psi pressure.
Hence why it is so important to keep filter clean and good quality.

 

unless the oil is too thick, as with cold starts.

I'm just relating the argument: it's been bandied a lot on BITOG by people far more knowledgeable than myself, and I don't have the wherewithal to settle it! Which probably wouldn't matter much 'cause reading through it sounded like results would vary with particular engine conditions and lubrication design philosophy of the engineering team at work.

They cut open quite a few used filters to find media split at the seams, both much-used and 'brand new' ones trying to discern whether they are bypassing (nothing definitive to me). I was surprised to find that filter media 'implodes', as you put it, a lot more often than I thought... and that what constitutes "quality" is not always what you might think it to be! I think the bypass pressure is 12psi in the filter I use.

Another reason to keep air filters clean

 

Straight up Mobil 1 I go 10,XXX+ miles...maybe I'm lucky, but I've never had an issue.

 

Straight up Mobil 1 as in conventional, and you go 10,000+ miles?!

Fink

 

Nah, I meant fully synthetic as opposed to "super-types." Sorry for the confusion.

 

Ok, whew.

Fink

 

I'm sure most car enthusiasts would consider it high, but I've always thought the intervals were greatly exaggerated; who knows, someday I might find out differently the hard way...so far, so good in 22 years of driving.

Damn, that makes me feel old...

 

x2

Common filter failures are possible. All I am saying is that normal operation is to not open bypass valve until filter is clogged. If filter splits inside or bypass valve opens then this is faulty filter.

What I do is
1. Use Toyota filter which does not seem to have seams because its one spongy material.
2. I Use synthetic so oil never gets too thick even when its dirty.
3. I make sure I make oil change right before winter.

12 Psi is possibility and I think it depends on the medium used for filtering. Would be nice if that was something that was provided on the package.
Maybe Chris can test them for us and provide numbers..

 

It's in the tech data book put out by the filter manufacturer.

If the bypass is indeed variable based on filter media, it would lead credence to a theory that the filters may by-pass in normal operation since there are many media types and filter mfr's.

 

I had never seen one. Post the link or numbers I am curious to see what all filters are set to.

 

Pretty sure bypass pressure is based on the bypass valve design. More restrictive media may cause the bypass pressure to be reached earlier/more often. Yes there are many media types and filter mfrs, and you run the risk of bypass happening more often when deviating from the OEM filter.

Ideally, to support extended OCI, you would want a filter that's identical to the OEM filter in design, but with twice the media area.

 

hahaha... I found the specs on my filter the old fashioned way. Not online but the catalogue hanging with the oil filters in the parts store... a Pepboys I think. You'll have to check your store to see if they have the catalogue for your fav filter mfr. so you can look at it. Used to be all parts stores had a huge catalogue collection at the counter and they'd let you look.

Would be nice if they would all have links on their web site wouldn't it?