Cadillac Forum - Enthusiast forums for Cadillac Owners

Quote:

Originally Posted by 92_Daddylac (Post 30046)

i just read that article and that answered alot of stuff i had questions about very good info. I guess i learned more about the differences between the two (synthetic and conventional oil) than i thought. Thanx for letting me know about that i will tell everybody that tells me that synthetic oil is better hands down.

When I asked where did you read that, I meant the bold item above ...
such is not in the thread .. https://www.cadillacforum.com/forum/...itor+algorithm

here are some highlights of the subject thread ...

Quote:

from the same GM Eng above...

Just to set the record straight...the use of synthetic engine oil does nothing to increase the allowable change intervals. There are many reasons to change the oil. The oil oxidizes with temperature and time. The oil becomes contaminated with gasoline and water from blow by and combustion byproducts. The anti-wear additives in the oil becomes depleted. While the synthetic oils may not oxidze as quickly as conventional mineral oils they become contaminated just as fast and the anti-wear additives in synthetics deplete at the same rate. Nothing magic about synthetics that allow them to remain in the crankcase any longer than conventional oils.

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There is little or no benefit in using synthetics in either the engine or trans in normal driving. Period.

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Synthetic oil offers one major advantage over conventional mineral oils....it can still function without serious degradation at oil temperatures above 300 degrees F. This is good...but....passenger car engines are designed and cooled so that the oil never gets that hot ...even under extreme conditions. If the oil never gets near 300...then what advantage is there in using an oil that its only advantage is that it can live over 300 degrees ?

Synthetic oil is the factory fill oil for several applications purely because it's high temperature capability allows the deletion of the oil cooler on the vehicle. Since the oil cooler is only required for the very few vehicles that get taken to the race track it is unnecessary cost , mass and complexity on most vehicles and creates a liability for leaks... If the synthetic is capable of protecting the few engines that go to a race track then it makes sense to use it instead of saddling every car in production with an oil cooler. The engine does not require it other wise. Neither does the trans.

I find it amazing that people change their trans fluid at 100K and find it necessary to put synthetic in. The trans made it 100K on the factory fill oil that was NOT synthetic...so what makes synthetic desirable now after 100K or more.?

A similar argument exists regarding the engine oil...

Meaning, that if your car calls for synthetic oil, it probably left the factory without a OIL COOLER or is equipped with a 500hp engine that burns fuel fast, very fast ...

Both MY GM cars have OIL COOLERS .. no synthetic oil there now, or next time ...
good ol' dyno oil does just fine even at sustained 110 mph+ in 100F ambient temps ...

What we also DO KNOW is that often, an engine running on dyno oil w/o leaks will develop a leak when changed over to synthetic .. reason? smaller molecules fit through smaller gaps and you got a leak where no leak existed.

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