Thread: Mmo
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Old 12-13-2011, 12:29 PM   #25
DIYguy
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Join Date: Mar 2007
Location: Northern California
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1997 SC2
Wrench Re: Mmo

Quote:
badbobby said- By deisel oil do you mean deisel fuel? in the oil pan??? Also why not piston soak? Yes I have heard a lot of good comments on seafoam. And yes walmart rocks on their prices on most oil products including synthetic oils.
No, absolutely not. I mean that you should use diesel oil such as Rotella or Delvac or Delo for your next oil change. It is typically 15W40 and I have seen no issues using it. I alternate between that and 5W30 full synthetic on oil changes and it seems to keep everything very clean.

As for Seafoam, I have posted their MSDS a couple of times. Basically if you buy about a quart of naptha, a quart of isopropyl alcohol (painting grade), and a quart of 3-in-1 oil, you can mix up a batch of your own (the wintergreen scent is optional). Or, just buy Seafoam....

Quote:
PlasticCarsRock said- No... he/she means diesel oil... oil designed and marketed to be used in diesel engines. While the detergents in diesel oils are not optimal for use in gas engines, they do tend to clean a bit better. Regular synthetic oil is still a far better choice, though.
He, actually. That's my wife on the hood of the car in the avatar (at a very young age obviously), and my sister-in-law who is an artist created the avatar. .

I disagree on the synthetic as a better choice as a hard rule. After I overhauled my engine I ran nothing but 5W RP and other synthetics for a long time so I wouldn't compromise my fresh overhaul. The problem is that any tiny little leak will be magnified using it. After fixing them all, I still noticed a long term trend toward using oil again.

I have diesel oil around for other "vehicles" so I tried it on an oil change and it came out a couple of thousand miles later absolutely filthy. But the minor oil usage basically stopped.

So now I alternate between them and it seems to work quite nicely. Even the synthetic comes out dark now. So I can only conclude that the combination is working to keep everything clean (plus I opened up the cam cover recently and it looks as clean as when I buttoned it up during the overhaul).

Oh, and I have noticed little or no meaningful difference in gas mileage when switching back and forth between 5W30 synthetic and 15W40 Delo. There might be some difference, but it's very small and lost in traffic and weather patterns, so I can't put a number on it. I use a tank a week and keep very careful records.

BTW I do use synthetic the BMW and my wife's truck (and even in the old Honda), but they don't have the oil ring problem that the SC2 has/had.
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DIYguy

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97SC2 Saturn (gone but never forgotten), Gen6 Camaro, Cruze Eco, Chevy SS P/U, Honda VT1100C, Honda CBX
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