I have just recently found out that if you use castrol gtx oil in your car it voids the warrenty, because GM does not appove the oil in there cars.. i found out by the owner of a oil change place here in austin... so yea i hope this information is useful to someone

 

Page 5-19, 2006Chevrolet Monte Carlo Owners Manual:

Notice: Use only engine oil identified as meeting GM standard GM6094M and showing the American Petroleum Institute Certified For Gasoline Engines starburst symbol. Failure to use the recommended oil can result in engine damage not covered by your warranty.

Soif you dump some oil into your car that doesnt meet the standards set by GM, then they can dishonour your warranty on certain things. Im sure some oils are superior, and some are not as good. I just get the oil done at my $tealer$hip just because the car is under warranty still.

 

[align=center]Members, Xavier& Ian,[/align][align=center][/align][align=center]Thanks for the information. I didn't know that Gastrol GTX is not approved.[/align][align=center][/align][align=center]I hope that Mobil 1 is approved by GM : )[/align][align=center][/align][align=center]I better read my owner's manuel again : )[/align][align=center]`Space[:-][/align][align=center][/align][align=center]I better read more......[:-][/align][align=center][/align][align=center]
More Than You Ever Wanted to Know About Motor Oil[/align][align=center]

Choosing the best motor oil is a topic that comes up frequently in discussions between motoheads, whether they are talking about motorcycles or cars. The following article is intended to help you make a choice based on more than the advertizing hype.
Oil companies provide data on their oils most often refered to as "typical inspection data". This is an average of the actual physical and a few common chemical properties of their oils. This information is available to the public through their distributors or by writing or calling the company directly. I have compiled a list of the most popular, premium oils so that a ready comparison can be made. If your favorite oil is not on the list get the data from the distributor and use what I have as a data base.
This article is going to look at six of the most important properties of a motor oil readily availiable to the public: viscosity, viscosity index (VI), flash point, pour point, % sulfated ash, and % zinc.
Viscosity is a measure of the "flowability" of an oil. More specifically, it is the property of an oil to develop and maintain a certain amount of sheering stress dependent on flow and then to offer continued resistance to flow. Thicker oils generally have a higher viscosity, and thinner oils a lower viscosity. This is the most important property for an engine. An oil with too low a viscosity can shear and loose film strength at high temperatures. An oil with too high a viscosity may not pump to the proper parts at low temperatures and the film may tear at high rpm.
The weights given on oils are arbitrary numbers assigned by the S.A.E. (Society of Automotive Engineers). These numbers correspond to "real" viscosity, as measured by several accepted techniques. These measurements are taken at specific temperatures. Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50 by the S.A.E. The W means the oil meets specifications for viscosity at various low temperatures depending on weight, and is therefore suitable for Winter use. 5W is tested at -25C, 10W at -20C, 15W at -15C, and 20W at -10C.
The following chart shows the relationship of "real" viscosity to their S.A.E. assigned numbers. The relationship of gear oils to engine oils is also shown.
[:-]Click below for source & Charts [:-][/align][align=center]http://www.micapeak.com/info/oiled.html
[/align]

 

i know they say that, and gm will try to squirm their way out of anything they dont have to fix, however..i know that with royal purple after getting off the phone with them that if anything happens to your car and it is CAUSED from the oil that royal purple will take care of it, but if it is not gm is forced to take care of it, the oil is sent to the oil company they analyze it, and if it is not caused from the oil(dont ask me how they determine this) then the dealership has to cover it no if,ands or buts!

 

The dealership told me the same thing when I put my K&N drop-in filter. As long as the filter didn't cause the problem, my warranty was fine. However the engine oil, obviously, is more likely to cause a problem than an airfilter.

 

I have been buying my Mobil 1 ex' perf' oil from my Chevy dealer, who does my oil changes. I know they approve it. Besides, as far as I know, new 'Vettes come with Mobil 1 in the crankcase, and anything else will void the warranty on them! Another reason I use Mobil 1, and the 15,000 warranty. The only mfg' with a warranty like that.

http://www.cardomain.com/ride/2319272

 

i have a rep that came in the store that wanted to test out the oils we have in the store, its by pushing a bearing onto some sort of wheel in the oil, you go until it leaves marks in the bearing....

he tested some of the synthetics

castrol made marks @ 4 lbs
mobil one @ 6 lbs
amsoil @ 5 lbs
royal purple @ 9 lbs


thats just the oils he was doing...basic 10w30 non synthetic was about 4lbs

he's an additive seller and he put his additive in and every oil went up to 27lbs...but even without that it shows which are better lubricants....but i think the argument on oil could go on forever...just thought i'd post that...because i just found that out a couple days ago