Originally Posted By: FZ1
No problem. I was just pointing out to the op that each person's drive/motor is unique. Just because you can run long drains in Conn.,does not mean the op should expect to do so in Tenn. in dirt and gravel. Look at his silicon.
Of course. I know that every one has good and bad days, and that some times, something that seems benign while typing can be misconstrued into something argumentative. The thing I prize most about this community is the discussion. Look, even Gary's chiding is friendly and conversational in nature... haha!
Originally Posted By: Gary Allan
I tend to agree with most of what you said.
UOA doesn't measure wear ..but most will agree that less is better. Even at higher levels this would still be noise ..so it's like measuring a 30' vs. a 25' margin.
I also agree about the 3750 OCI. Anyone who has seen a GM OLM'd car vs one using the calender/odometer has to realize that static mileage/month recommendations have substantial fudge factor to create an envelope that will fit the most consumers inside it. Americans are way too disinterested consumers to differentiate between severe vs. light duty. The engineers and accountants have to apply KISS for the typical owner.
To think that some invisible spring trap slams shut @ 3750.9 miles is a bit comical if you think about it. That was the CYA figure to inhibit the ruthless American consumer from, as always, trying to get away without paying for their behaviors. Savagely insisting that they did nothing wrong and it's Subbie's fault for selling it to them.
(an opinion based on personal use and observations) K&N filter work okay. The filter appeared to have X number of cleanings until the silicon numbers started to climb. I think cleaning them too often would shorten the functional life span. Mine was in a common engine. Something that gulps lots of air will probably see some more hp @ limits ..and will probably see a touch more contamination.
If this was an LTR car, I would offer that longer term, abrasives could alter the efficiency of the turbo due to impeller erosion. I don't know if it would be enough to notice.
Most will agree that less wear is better because we all tend to fail conservatively. In my mind, if the oil looks good, then it'd doing it's job. If the motor is being pushed to the point where it's wearing excessively, but the oil properties are sufficient, then it's either a mechanical or environmental issue, not a lubrication issue.
As far as K&N filters are concerned, almost every one I've known who has run them has either cleaned them too often or over-oiled them, leading to MAF or other issues. For a FI car especially, the waste-gate duty cycle, turbo dynamics and tune will have more to do with performance than the filter material. From what I've seen, power does not change, and neither does spool time for simple drop-in-filter mods, at least for turbo Subies. There has recently been some-what substantiated gains using cold-air intakes in conjunction with single high-flow cats, and unsubstantiated cold-air-intake-only mod gains.
Originally Posted By: MrWideTires
Having been dealing with Subarus all my life, and I have an STI myself.. I can tell you guys, if you insist on extending your oil life on every car, please don't buy a turbo subaru.
It doesn't matter how "oh it looks like it still has life" it looks, turbo subarus simply do not like going over 5000 miles on an oil change, even the most expensive synthetic.
These are NOT cars to be playing around to see how many extra hundred miles you can get, or run conventional because "synthetic is a waste at that short interval", you'll pay for it on the long run.
Being an engineer, I'm always after maximizing efficiency. I'm perfectly happy with my STI and a stage 1 retune - stock components, reflashed ECU - so the idea that failure = upgrade doesn't appeal to me. I plan to run my STI into the ground, with a sufficiently conservative maintenance schedule. For things I don't know enough about, like differential fluid, brake fluid and power steering fluid, I'll stick with a mileage schedule. Luckily for me, there's a tool, UOA, that can be used to determine approximately how long an oil can be run in my application before it's beyond the point where it's sufficiently protecting my engine.
I know it's hard to see "risking" something as expensive as a turbo or motor on something so silly as oil, but I'm confident that the data I have, and will use it as a guide. There's really no excuse for paying so much for a UOA if you're not going to use it as intended, except for pure entertainment value or peace of mind.
Besides, didn't I read somewhere, that most oils chemistries take a certain amount of hot hours before tribal layers are formed on the bearing surfaces?
Originally Posted By: webfors
I wouldn't push a turbo subaru past 5k personally, and if it's under warranty there's no rational reason to that would offset the potential of Subaru not honoring your warranty.
I've seen your posts and respect your opinions, but can't agree here. Like ANY car, the OCI has to be based on environmental variables as well as the oil itself. Where Rotella T6 may only last 7kmi or less in my STI with my driving style and environment, it may only last 4kmi for some one else who live in NYC and rally X's to work every day!