Oil Question
#1
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Oil Question
Why is "Marine Oil" 20w 50 or 25w 40 or such. Why not 10w 40 or 15w50. I understand the second number higher being better for long high rpm runs but whats with the first number. I would think lower is better. Less time to get the oil pumping.
Chris
Chris
#2
Actually for a boat, the first set of numbers really don't apply to us......that's the rating for cold weather operation...since we don't boat in winter conditions the second number is what you should be looking at ....
The "W" incidentally stands for winter....so like i said...don't really apply to us.
The "W" incidentally stands for winter....so like i said...don't really apply to us.
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-Wally
Money can't buy happiness, but it can buy horsepower. And I've never seen a sad person hauling a$$!
-Wally
Money can't buy happiness, but it can buy horsepower. And I've never seen a sad person hauling a$$!
#3
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A while back I switched over from standard merc 25w40 to Rotella T5 Semi Syn 15w40 in a stock Merc SBC. I seemed to have found 100 RPMS doing this. I know it sounds like BS but it has been a consistent result for me. So far no problems. Anyone see any drawbacks to this oil. I'm sure there is better oil out there but this is a stock merc SBC. It see's 70% of its time 1000 RPMS and 30%of its time at 3800-4000 rpms with a run up to 4400 rpms for about 1 min each time we go boating.
Chris
Chris
#4
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I have found some extra rpms with heavier oil...but I am opposite of you, I run the piss out of mine.
I just look at WOT performance, not lower rpm.
Example: Going for a WOT run this past week-end my sbc was at 6200rpm. Hydraulic roller.
So, in my case, even though some disagree, but I'm old and have run the schit out of many valvetrains, my hydraulic and hydraulic roller engines are more stable at higher rpms with thicker oil .
In your case, there is no valvetrain hydraulic issues to worry about, therefore your results are from reduced fricition. And yes, this can happen between oil brands, and more typically oil weights and synthetic vs non.
The reason why so many car manufacturers use syntetic drivetrain oils is because fuel mileage. Plain and simple.
I just look at WOT performance, not lower rpm.
Example: Going for a WOT run this past week-end my sbc was at 6200rpm. Hydraulic roller.
So, in my case, even though some disagree, but I'm old and have run the schit out of many valvetrains, my hydraulic and hydraulic roller engines are more stable at higher rpms with thicker oil .
In your case, there is no valvetrain hydraulic issues to worry about, therefore your results are from reduced fricition. And yes, this can happen between oil brands, and more typically oil weights and synthetic vs non.
The reason why so many car manufacturers use syntetic drivetrain oils is because fuel mileage. Plain and simple.
Last edited by SB; 09-10-2015 at 10:52 AM.
#5
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Ahhhh, another oil thread, just one comment, You wont find me running a Diesel oil in my marine engines
#6
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And now I am explaining on almost a daily basis to customers about oil consumption. Between 10K mile oil change intervals, low tension rings, and 0W20 piss-thickness oil, yeah, your little high revving 4 banger is going to use a couple of quarts. The unwashed masses are having to learn how to check the magic wand under the hood every now and again to see how much oil is in the motor.
#7
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Wanna know how I stopped having to explain ?
No more 5W20...they get 5w30. And 3-5k oil changes. Synthetic 5k, regular oil 3K. Most come in at correct time.
Only vehicles I have that use oil / have low oil issues are old POS Subarus that should be thrown out soon for other issues. LOL.
No more 5W20...they get 5w30. And 3-5k oil changes. Synthetic 5k, regular oil 3K. Most come in at correct time.
Only vehicles I have that use oil / have low oil issues are old POS Subarus that should be thrown out soon for other issues. LOL.
#8
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So what do you run 33 outlawsst. I know lots of people running Shell rotella T.. Not sure about the T5. Anyway I am just looking to see if there is anything wrong with the T5 or 15w40. My Main reason is they sell it at Oreilly and Orilley also has the filter I use which is a wix 51515. And I'm sure that is a whole nother debate. I dont have a bone in that fight its just convenient for me and I want to make sure its ok for my motor.. Has been so far. Maybe Oreilly will start carrying Brad Penn...lol... Just kidding.
Chris
Chris
#9
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http://www.walmart.com/ip/Mobil-1-15...5-qt./20713647
4.78 a quart and free shipping if you order more than one is pretty hard to beat for full synthetic.
4.78 a quart and free shipping if you order more than one is pretty hard to beat for full synthetic.
#10
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Actually for a boat, the first set of numbers really don't apply to us......that's the rating for cold weather operation...since we don't boat in winter conditions the second number is what you should be looking at ....
The "W" incidentally stands for winter....so like i said...don't really apply to us.
The "W" incidentally stands for winter....so like i said...don't really apply to us.