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10W 40 weight engine oil better for 4.0?

R

Rudy96'

NAXJA Forum User
Location
U.S.A.
I heard a good freind and mechanic say that 10W 40 is a better weight oil to run in the ol' straight six rather than 30 weight. Would this be a good thing or a bad thing to try? To Me it makes good sense that a engine that runs at 210F all the time would run smoother and better on a thicker oil. So guy's what do you think?
 
No..I was told to do that years ago. Have I been doing it in the wrong order? I dont even know why he said I should do that. What is the purpose in it?
 
The manual says 5w30 in the winter and 10w30 in summer
 
HaZakated said:
No..I was told to do that years ago. Have I been doing it in the wrong order? I dont even know why he said I should do that. What is the purpose in it?
Click to expand...


You want a lighter weight oil in the winter to allow the oil to flow better when cold.
 
Never really stoped to think about it but your right....Its just common logic. winter you need thinner oil.

Wal -Mart sells those 5qt bottles of synthetic oil for like 10$ here in ohio. If you go to Auto Zone or some place similar, you would be lucky to get 1 qt. for less than 3$. Guess since they sell the oil in bulk 5qt bottles they can sell it cheaper. including a filter, I can change my oil here in ohio with synthetic oil from wal-mart for like 15$, give or take a dollar.
Brian
 
Last edited:
Sometimes I luckout and find pennzoil on sale at the Walmart by me for like $6.50 for 5qt jugs. i haven't seen it that cheap in a while tho.
 
Rudy96' said:
I heard a good freind and mechanic say that 10W 40 is a better weight oil to run in the ol' straight six rather than 30 weight. Would this be a good thing or a bad thing to try? To Me it makes good sense that a engine that runs at 210F all the time would run smoother and better on a thicker oil. So guy's what do you think?
Click to expand...
Yeah, 10W40 is better. That's what I ran in my '88 for 175,000 miles, before I fianlly switched to synthetic. Now I run 5W50.
 
Woah that's some thick A oil your runnin. Sounds like good thing to me so I think I'll give it a try. Thanks Eagle and all at Naxja.
 
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