Is this Delvac a no go ? I know it has to be dumped every 5k...
Thoughts and or expert opinions ?



coyote wrote:Mick,
Cts is Carats, cSt is Centistokes.
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I think you've moved beyond looking at the 5W30, 10W40, etc that's on the label and should be discussing the technical specs from which those numbers are derived.
It used to be that only thick oil had good film strength, but that's just no longer the case. Top shelf modern synthetics are simply amazing in this regard. It's due to something called reptation where the molecules line up like snakes when in a film under pressure and just don't split apart. Additive packages then help, but they degrade more quickly than the base stock.
You want an oil that keeps the bearings apart, but flows well enough to keep everything cool and clean. That is designed into the engine, the oil pump and all the channels through which the oil flows. An oil that is too thick to get pumped around each rev won't be doing it's job as well.
I've spent maybe 20 years reading up on tribology and am still nowhere near understanding all this, but I think you are basically correct in your approach to go with a specific oil for your two very different applications (street and track). There is no one size fits all solution, despite people's desire to stick with one oil in the same way they never switch beers.
Most cars on here are road cars. They need an oil that flows at a rate of about 11 or 12 cSt at 100C. The further from that they are when cold, the more startup wear. But of course we aren't standing on it until after the oil is warmed up, are we?
If you aren't already doing so, start looking at the HTHS numbers of the oils you intend to use at the track. For the street use oils, also check the TBN.
Then of course test it. Reading forums, asking for advice and staring at spec sheets for nights on end is no substitute for actually testing how your oil is performing in your engine under your application.
At the end of the day, most engines don't fail and many that do, do so for reasons not related to oil. We could probably all use home brand oil and have only a 1% failure rate. Who wants to be the 1%?
Rome_STI wrote:You do my head in. I just want a simple solution.
Rome_STI wrote:I am currently using Motul Turbolight 10w40 (will double check this when I get home as I am not 100% sure).
Rome_STI wrote:So what I should do is test this oil? How would I do this?

coyote wrote:Note that Mick will give you a hard time because it's not SM rated. He's right, but I reckon the smaller companies should be cut some slack when it comes to retrospectively getting old oils approved.

chaotic2050 wrote:bass_straitener wrote:chaotic2050 wrote:I spoke to Ross Cromwood last week if he had heard of anyone using Delvac oil in the 2.5 turbo subarus and he said no. Might only be used by a few people with major engine work?
Ring Ross tomorrow and check again, I'm sure he's heard of one at least now.
I actually asked him specifically about you at the time and that you were planning on using the delvac oil but I don't think he was quite sure who I was talking about.

dr20t wrote:Read my post (read: essay) on the previous page
Mick
dr20t wrote:Read my post (read: essay) on the previous page
Mick

coyote wrote:dr20t wrote:Read my post (read: essay) on the previous page
Mick
Penrite specs are stupid.
No TBN for your daily driven oil and no HTHS for your race oil.
I also think they make a decent product, but it's as if they don't want you to know some of the most important info.
senator wrote:I pretty sure there was some TBN and NTHA in the last MSG infused Asian meal I had.

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