What do you use? Options

[turbohcar]

I know it's been talked about before, but I'd like to go a little more in-depth. Oil. Which grade to be more specific. I've read a couple VFAQs on it and had experience choosing oil (I change oil for a living at a Dodge dealership) for different vehicles. However, the only vehicle I am concerned about with this post is the 4G63T motor. Post what you use and why you use it. Like I said, brand isn't as important because most of the time it's a matter of opinion, it's more about the grade.
Right now I'm using Cenpeco 5w30. It's a paraffin wax based oil that is made for high performance vehicles. Pretty expensive but worth the price for an all race motor. I'll be switching to Valvoline Synthetic here the next oil change but I'm not sure yet which thickness. Thanks

[natedogg]

I have always used Mobil 1 synthetic with good results. I used 10w-30 before rebuilding my engine. After the rebuild I broke her in with SAE 30 Valvoline dino oil, and then regularly ran 15w-50 Mobil 1 in her because I figured the tolerances were not quite factory tight anymore. I have since then gone back to 10w-30 after a few high pressure spikes have blown out my oil filter gasket. I don't think it was a result of the heavier oil, but the lighter oil will help keep the overall pressure down. Just a quick summary of my oil experiences.

There is some good oil info on this web page:
http://www.chris-longhurst.com/carbibles/i...eoil_bible.html

[turbohcar]

I was thinking much the same thing. How heavy is too heavy, and how light is too light. In the hornet racecar we've used the Cenpeco and it's seems to do the best. Mainly because we run the car in between 6k and 8k the whole way around the track. Mostly at work, we put 5w30 in almost all newer cars/trucks. I want to go to Valvoline because I've always had good experiences with it and I'm afraid the paraffin wax may cause gunk buildup.

[turbohcar]

http://www.dsm.org/archives/1996/09/19960930.txt/10.html

That's the link I was looking at.

[SCCA Stang]

I use Mobil 1, 10W30 in my GSX... just so happens the same oil I use in my EcoTec Cavalier

[turbohcar]

Mobil 1 is also another very good choice for oil blend sensitive motors that I've noticed (not to be confused with regular Mobil). Currently, the three tanks we have for oil at work are filled with Valvoline 10w30, Mobil 5w30, and Motorcraft 5w20. All of them seem to be reputable oils for dino oil. One motor oil I'll never use is Penzoil. It seems that something that is sold by Walmart in their oil change bays just isn't good enough for my car. That's just me talking though. I'm using the Mobil 5w30 in my S10 and it is rather happy with it. When I had 10w30 in it at first it really didn't seem to perform quite as well.

For the newer vehicles (100k or less miles and post 1990) I usually use the 5w30 unless otherwise specified. Anything older, more miles, or just in poor condition and I put the 10w30 in it. The 5w20 is mainly for Ford products from 2000 on and some 2005+ Dodge Caravans.

Alldata also says to use 20w20 or 20w40 for temperatures above freezing, 10w30 for temps -5 to 32 F, and 5w30 for anything below -5. Granted the source isn't entirely credible but can this really be true? I've also seen charts for the Turbo T/E/L that says 5w30 below freezing, 10w30 above. I guess this is the source of my confusion about which thickness to use.

[JMoushon]

I have always run Mobil 1 15w-50, with straight 50 weight VR1 in the summer. I've found that it reduces the haze that is inherent at 20+psi. I also put 1pt of lucas oil stabilizer in at every change. Helps reduce lifter tick, and I'll happily sacrifice 10hp for solid lubrication.

[turbohcar]

LOL, my car has lifter tick even after I shut it off. But, that has something to do with the raised oil pressure, nothing to do with grade. Please describe this haze you experience James. Not that I'll experience 20+ psi in the near future but it may be a sign of a better oil.

[JMoushon]

Hazing is the limited amount of blow-by inherent on an old engine at high boost. In reality, even newly built race engines (often, not always) have tolerances that are "out of spec" as per the manufacturer, so it would apply to them as well. Watch at Cordova when any of the hi-psi cars run, and there will be a limited amount of blue smoke that follows behind. Also, I've noticed that the same thing happens to a hi-comp Hondar when on the bottle or boost, so I would assert that it is caused by extreme chamber pressures, not just boost.

[turbohcar]

I see what you mean. I guess my final question is, how does an oil reduce blow-by (past the rings I am assuming)? I'm not expecting you to be an expert at why, it's more that I'm curious as to what gives it this charicteristic and not other oils.

[JMoushon]

For the same reason that vegetable oil would not seal the cylinders as well as motor oil. A thicker oil has more ring sealing ability, which is why products like "motor honey" and lucas stabilizer reduce smoking (blowby) in worn engines. All those things do is add a few chemicals and thicken the oil. The chemicals may or may not help, they could easily be "snake oil" placebo-type stuff. Not sure on that end.

I was not asserting that a particular brand seals better, I was stating that based on viscosity.

[SCCA Stang]

For the same reason that vegetable oil would not seal the cylinders as well as motor oil.  A thicker oil has more ring sealing ability, which is why products like "motor honey" and lucas stabilizer reduce smoking (blowby) in worn engines.  All those things do is add a few chemicals and thicken the oil.  The chemicals may or may not help, they could easily be "snake oil" placebo-type stuff.  Not sure on that end.

I was not asserting that a particular brand seals better, I was stating that based on viscosity.

I tend to agree with you on this as I have noticed more "blow-by smoke" out of mine at higher boost levelsand RPM's w/ 5W30 Mobil 1 than w/ 10W30 Mobil 1

I only run the 10W30 in the Cavalier in the summer... in the winter, I run 5W30 in it