- Sep 22, 2007
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- 2.9 V6
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- 177 CID
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- A legend to the old man, a hero to the child...
Im not even a fan of the blended...but honestly its hard to find 10w30/40 dino unless you pay crazy prices at the parts store for itThere's not nearly as much difference between synthetic oils, and the 'dinosaur' oils as you might think. Synthetic is still just oil - it's that all of the oil molecules are closer to the same size. That is accomplished by distilling the oil after going through the refinery process (cracking). Advances in refining brought conventional oils closer to synthetic in the late 90s and I think there were in fact some lawsuits flying around, as memory serves, between the "original" synthetic producer(s) and some of the newer stuff, but the courts upheld oil companies claiming "synthetic" no matter how they got it. Anyway......
Oil isn't just oil. There's "stuff" in it to keep the integrity of the seals good, among other things. Remember Valvoline coming out with the "Max-Life" oil? They just added a lot more of whatever is good for the seals to regular oil (at the time, they probably have a synthetic blend too). That stuff works. I made the mistake of putting Mobil 1 in my 68 Bronco back in the 90s, and it proceeded to leak like a screen door on a submarine..... oil EVERYWHERE! Changed out to Max-Life and the only things that leaked after that were the steering box and front pinion seal, neither of which of course had engine oil.
Anyway, when my 97 started leaking at the rear main seal (250,000+ miles) I started dumping 4 quarts of the usual Mobil 1, and a quart of Max life in it, at each change. That helped, a little. But of course the RMS needed replacing and that got done when the transmission was rebuilt.
You can mix different brands and even weights. Weights on oil are just an average of the viscosity of everything that's in the bottle. Big molecules, small molecules, etc. Mix 0-20 and 10-40 half and half, and you end up with 5-30 or thereabouts. Even with "full" synthetic, there is some "regular" oil mixed in, to help keep the additives in suspension. The reason your oil comes out thicker when you change it, than when you put it in, is that the lighter molecules in the mix tended to burn out before the heavier molecules. Unless you have a carb running way rich in which case the oil has a lot of gasoline in it......
Bottom line, oil is oil, and people who think that synthetic is some magic creation are flat out wrong. It's just a more consistent bottle of the same size oil molecules - plus whatever additives the manufacturer sees fit to put in.