Are Longer OCIs A Bad Thing?

Status
Not open for further replies.
I remember Mobil 1 advertising 25,000 mile OCI's back in the 70's IIRC it got them into some trouble.
 
It got the 5w-20 retired for a long time. It also started a long string of disclaimers. Turbo, diesel ..etc. My mother used it for the 25k/one year deal throughout the whole thing.
 
I run my Subie 7000 miles on Mobil 1, all highway miles, not in an extreme climate. I haven't done a used oil analysis because I don't think I need too, the oil is still a medium amber color, even after 7000 miles. I could probably get away with 8K on an oil change.
 
I kept my OCs at 5000 miles on M1 with my old Pontiac Grand Prix and on my Monte because of GMs LIM/UIM issues - this was exactly my thinking. If the worst happens, I don't want even trace amounts of coolant mixing with my oil. I started stretching the Monte closer to 7500 miles after I found that the LIMs were made of the updated gasket material, and I never had a problem with the GP after 130,000+ miles. Also kept a close eye on coolant levels, but every bit of paranoia helps. Sniff tests have revealed fuel dilution in the past with my Firebird, but she's been seeping so much oil around leaky oil pan gasket, and possibly others, that I don't stress about that too much yet, suspect short trips combined with recently resolved misfire issues. Definitely keeping an eye on OTHER fluid conditions than oil (coolant level, basic oil dipstick condition scent and appearance) helps, but I'm paranoid like that.
 
Commonsense tells me the longer the oci, the longer (the dirt) and the more dirt will be in the engine. regardless of oil/filter, dirt is dirt. thats my thoughts.
 
Originally Posted By: kcfx4
Commonsense tells me the longer the oci, the longer (the dirt) and the more dirt will be in the engine. regardless of oil/filter, dirt is dirt. thats my thoughts.


There should be no dirt in the oil. Air filter keeps it out. A good oil filter is 10 or 15 micron.

Would you believe these are all at 10K miles?

UOA8-28-08.gif


D82610_1.png
 
Originally Posted By: kcfx4
Commonsense tells me the longer the oci, the longer (the dirt) and the more dirt will be in the engine. regardless of oil/filter, dirt is dirt. thats my thoughts.


"Common sense", science, and engineering are not the same things. The term "common sense" is grossly abused in our society, usually as a cover when there's no real basis for some belief that the believer wants to hold on to.

So let's break this down some. First, define "dirt", precisely please. Without knowing what the dirt actually is, or how big the particles are, you can have no idea of what, if anything they will do in your engine. If the dirt consists of particles large enough to be filtered, well, they'll be filtered. Are they hard material or soft? And so on.

Regardless of oil? Well, oil, and its individual ability to suspend or dissolve contaminants, will have a major impact on the end results. So you can't just say "regardless" in this context.

Filtration? Same as above, as for both the "dirt" and the oil. If you already have an inherently clean engine, the filter may not make much difference. In most cases, it may not. But still, there are differences.

At any rate, we see many many examples of owners successfully running appropriate, extended OCIs without difficulty. Irrespective of what's in there and when, the oil is doing its job, and the engines are doing just fine for as long as anyone cares to own the car.
 
dirt as in ANY debris/contamination/etc...........think what you want and ill do the same..i use edge and m1 in different vehicles, neither one see more than 6k on an oci..... wich i guess makes me wrong for 2 reasons on this site..#1 too short oci....#2 not using Pennzoil Platinum or Pennzoil Conventional
 
Originally Posted By: kcfx4
dirt as in ANY debris/contamination/etc...........think what you want and ill do the same..i use edge and m1 in different vehicles, neither one see more than 6k on an oci..... wich i guess makes me wrong for 2 reasons on this site..#1 too short oci....#2 not using Pennzoil Platinum or Pennzoil Conventional


No one should critize you for 6K OCI with M1 or others. But 10K OCIs are easy with M1(my only experience) and your engine will perform great at that level with no problems.
 
Last edited:
Status
Not open for further replies.
Back
Top Bottom