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which oil do you use?

  • 5w20

    Votes: 3 1.1%
  • 5w30

    Votes: 182 68.7%
  • 10w30

    Votes: 63 23.8%
  • 10w40

    Votes: 17 6.4%
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Discussion Starter · #1 ·
I was just wondering what oil do you use?

and what makes the diffrence in oil specs diffrent, for instance 5w30 like most of us use, what weight is that oil?

will using a lighter oil weat the motor? wouldnt make the motor more power since less weight to move around?
 

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If you use what GM recommends, you won't go wrong :z:
 

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Mobile One 5w30 every 3k or 6 Months! :D
 

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This has been beat to death. 5x30 mobile one, southern states or hot summer 10x30.. :drunk:
 

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Discussion Starter · #5 ·
you didnt get my point!!

IF Its been beaten to death, where?


but really what I mean is not for my use! its out of curiosity, will lighter oil make the motor rev free and give more power?

Just out of curiosity, what is the lightest oil ?
 

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Actually using a lighter oil will produce more HP...but will it protect as well? In instances where you are trying to get every bit of HP you can; isn't that also where you are stressing the engine the most, such as in competition.

There have been studies and tests done to support your supposition. For instance a specially formulated race oil that has friction modifier chemistry, electrostatic adhesion properties and high shear resistance has been marketed at 0W20 and shown to produce higher HP and Tx. This oil while running at low viscosity will cut oil drag but will maintain a low wear film on stressed componants.

Here are the result comparisons:
15W50
Baseline Max HP @ 9750 RPM
Baseline Max Tx @ 7300 RPM

5W40
+ 3.7 HP @ 9750 RPM
+ 1.9 Ft# @ 7400 RPM

0W20
+6.5 HP @ 9750 RPM
+3.1 Ft# @ 7400 RPM

The Lower Vis, Special Racing Oil netted a 5% HP increase and a 4% Torque increase. It's interesting that the Max. Tx figure was achieved at +100 RPM with lighter oil. It was also noted in these tests subjectively that the driver thought acceleration was better and throttle response was a little crisper.

You must also be concerned with oil pressure and oil flow under these conditions. Using this Low Vis oil would require a ported and polished oil pump, possibly a larger oil pump, a higher pressure output spring and higher pressure shimming. I would also recommend changing the oil after each event.

On the other side of the coin many competitiors in stock classes experience lower than normal pressures during competition in hot weather. They opt for the higher Vis 15W50 which flows as well in hot conditions and offers (normalized) higher pressures.

Bottom Line. Use a quality Synthetic. Use a higher Vis if competition oil pressures drop too low during hot weather events. You may consider a Lower Vis Racing Oil (for HP & Tx gains) but you must also modify the oil pump for higher output and be sure the oil has friction modifiers an adequate shear resistance for racing.
 

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Not another oil thread !!!!!

COUTO1981 said:
I was just wondering what oil do you use?

and what makes the diffrence in oil specs diffrent, for instance 5w30 like most of us use, what weight is that oil?

will using a lighter oil weat the motor? wouldnt make the motor more power since less weight to move around?
Short answer it's a 30 weight the first number has nothing to do with weight just it's ability to flow at colder temperatures . It is not a 10 weight oil when it gets cold . I can't think of any fluid that gets thinner as it gets colder can you . I use Amsoil series 2000 0 W 30 I have experienced no drop in pressure at all . I suggest you do a Goggle search for " THE MOTOR OIL BIBLE " it's a good read . Maybe you could add 0W30 to the poll JMHO :cheers: :cheers:
 

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My actual experience.

I have vettes oil changed every 1,000 miles or less.

I have no experience with Amsoil. So I will not comment on it. May decide to play with it in the future.

Fully Built N/A 429. Ten quart capacity.

Mobil One 30 just sucks. It just not good to have a single weight in an aluminum motor. The tolerences are little more than iron blocks and the aluminum blocks expand and contract more. Bottom line, burns oils and goes bad quickly with on/off stop and go driving. A litter higher temp as well.

Mobil One 5-40, 10-40, Pretty good.

Going to get this done in few minutes. The new Improved Mobil One 15-50w, going to use this with a K&N filter. Car currently never gets over 195 degrees(idling or racing(zero heat soak)) with the 10-40. I have ACP vented hood, electric pump, Haltech front screen, cut driver's side molding, etc., etc..

I will report back to forum, after I cook this batch of 15-50w. Should be more difficult.
 

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I don't think the general has our interest in mind but maybe the engineers do so I will use what the book calls for.
I have no racing issues pertaining to a 5 hp increase.
There are too many other variables to address in a compitition situation.
MHO :screwy:
 

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COUTO1981 said:
and what makes the diffrence in oil specs diffrent, for instance 5w30 like most of us use, what weight is that oil?
COUTO,
The first number roughly equates to the cold or "w"inter weight rating, the second to the hot (or normal) rating. But, don't think the oil is thinner when cold, it isn't. Cold oil is much much thicker than hot oil. Further complicating it, there are bands around what each weight rating is. For example, a 30 weight is defined as having a viscosity (cST) of 9.30-12.49 at 212F (100C). That is a pretty wide range. So when you buy a 30 weight, you can be getting an oil that has a hot viscosity of 9.31 or you might be getting one that has a hot viscosity of 12.48. You have to look at the oil data sheet for the oil to know what you are actually getting.

For example, most people will think that a 0w30 is "thinner" than a 5w30, but that isn't necessarily true.

From the manufacturer's data sheets for AMSOIL Series 2000 0w30 and Mobil 1 5w30

Viscosity 100C
AMSOIL 0w30: 11.2
Mobil 1 5w30: 10

Viscosity 40C (roughly the "cold" viscosity)
AMSOIL 0w30: 56.9
Mobil 1 5w30: 56

So you can see that the AMSOIL 0w30 actually has a 10% higher viscosity "cold" and a slightly higher viscosity hot than the factory fill Mobil 1 5w30. :cheers:
 

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My $0.02,

I just changed my oil from whatever was in the car when I bought it (Mobil 1 ???) to Redline 10W30. I went to the higher vis oil because I am running around 220 deg (oil temp), pressure around 40 lbs at 3-4K rpm, just fooling around on the street, not beating it much.

I am going to run Watkins Glen where I will be on it much harder. I was uncomfortable with the kinda low pressure, knowing it will go lower when the oil gets really hot - stock cooler.

The 10W30 seems to have accomplished the pressure goal. With the oil temp at 210 deg. I see pressure around 60 lbs at 4K rpm. Hopefully it will stay up at higher temps - we'll see.
 
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