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Re: [T3] Forward creep in neutral


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   Toby Erkson  --  air_cooled_nut@pobox.com
   '72 VW Squareback, '95 VW Jetta, '81 Gold Wing, '73 Porsche 914
   http://www.icbm.org/
   Portland, Oregon



Jim Adney wrote:

...The dino oil itself does not break down and can be re-refined and reused.





Huh? Dino oil certainly DOES break down. And synthetic can be recycled, too.



Everything I've read states quite clearly that the petroleum base does not break down in use. It's only the additive package that suffers. The additive package is VERY important, however. Recycling just removes the dirt, and spent additives and then adds back the necessary additives.


http://www.pelicanparts.com/techarticles/mult_gas_and_oil/mult_synthetic_faq.htm
One source I remember stating oil breaking down. There were others as well but, alas, I am at a loss of their location. Maybe they mean the additive package but even still, synthetic oil will out-perform conventional oil. Those additives are quite necessary as you know.


...

I've not heard anything about recycling synthetics. Does it need to be collected separately or can it just be recycled with regular dino oil?


Recycled with regular oil. I recycle mine at the local GI Joes store and they don't care. Same for my neighborhood's curb-side recycling.



The advantages of synthetic oil completely disappear if you don't have a full flow engine oil filter...



Not true because it still provides better lubrication than conventional oil...which is why one cannot break-in an engine with synthetic, conventional must be used first. After the break-in the synthetic oil can be used.



I think I've heard this both ways. It's certainly true that engines a long time ago were expected to wear quite a bit at first, but my impression lately is that finishing techniques in modern engine machining has greatly reduced this.


Still gotta break-in with conventional before using synthetic unless the engine builder states otherwise. Porsches and Corvettes come stock with synthetic oil (as do a few others), turbo'd or not.

I recorded an averaged 5hp GAIN by switching my engine and tranny oil to synthetic in my VW Jetta (NOTE: The Mk.III trannys come stock w/synthetic but I refreshed it during my testing).



Maybe the synthetics have an advantage in film strength, which allows them to be used in lighter viscosities. Did you test different oils with the same viscosities?


Conventional was 10w-30, synthetic was 15w-50. Technically speaking, the conventional would be thinner than the synthetic at temp. (For those that don't know, read up on oils at this web site: http://www.chris-longhurst.com/carbibles/index.html?menu.html&engineoil_bible.html

Viscosity is about mid-page.)

How did you measure your HP increase? What do you mean by "average" when you just have a single sample?

Used by G-Tech accelerometer for testing, strictly adhering to the instructions and I never said it was just one sample ;-) 5 runs with fresh conventional oil (changed at house, drove to testing road, about 15 minutes away). Dropped the best and worst runs and averaged the remaining three. Drove home. Changed oil to synthetic, drove to test road, 5 more runs. Dropped best and worse runs, averaged the remaining three. Warm day, temp. consistent (and likely humidity but I didn't test for that) and gas tank refilled to equal first run (1/2 tank, actually a little bit more in volume then the first run).

How many miles were on your Jetta when you did your testing? I'm asking because you would expect some increase just from whatever breakin occurred in a new engine.


I bought it used with over 45K miles on the odometer. It had 47.5K miles on the odometer when I did the testing.

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