Audi Junkie

Ever see old oil and water mixed? Not a pretty sight. That's what is going on inside your engine after water condenses *inside* your crankcase. On a dewey morning you see how much water condenses out of the air, and the same happens inside the block and mixes with whatever oil is in there. So going a long time w/o change means going with contaminated oil. The best schedule is one that lets you have the best oil quality when you need it the most, that is the hot of Summer and the cold of Winter. The big temp swings of Fall and Spring is what messes up your oil. So, I go for it November and May, tossing the contaminated oil out. Back to my original question. Does synthetic oil necessarily break down 1/2 as fast as dino? I know it is an isolated molecule that has better properties. That particuar oil is "cloned" so 100% is the same. It flows well, had less deposits but does it break down slower? I would tend to think the basic properties of the hydrocarbon chain is retained as far as breaking down due to shear. Dino has many slightly different molecules and isomers that all have the same type of covalent bonds. Why *wouldn't* it break down just as fast?

I am trying to make two points.
1) Oil gets contaminated in your car no matter how good it is in a lab.
2) Even if there is no contamination, why put faith in long intervals just because it is synthetic? I have not seen a reason to.

bltzkrg

Doesn't the engine get hot enough to "boil" that condensate off? It seems that it would turn back to vapor and exit the same way it entered.

Reggie3

The filter will remove lots of them but not all - also there are some chemicals that form from the water and other contaminates in the oil that cause problems.

Frankly - I change at the recommended intervals - and I use Mobil 1.

Audi Junkie

Sounds like a messy brew, what would happen if you tried this at home?

Audi Junkie

Reggie, do you mean 5k or 10k? What about "Severe Operating Conditions" as in the manual?

Audi Junkie

after detailing it!

April

Redline does a great job of explaining things.

http://www.redlineoil.com/redlineoil/engoilti.htm

Here a break-down of more info - note the ash and zinc numbers.

http://www.vtr.org/maintain/oil-overview.html<ul><li><a href="http://www.c5-corvette.com/redline.htm">Rear end comparo test</a></li></ul>

Audi Junkie

Interesting article. I forgot about Positive Crankcase Ventilation, even more oil contamination.