[~JC~]

OIL:

What the numbers mean. The numbers in motor-oil nomenclature refer to the viscosity (thickness) of the oil. A higher number corresponds to thicker oil, while a lower number refers to thinner oil. The numbers themselves are supposed to correspond to a set of real, measurable qualities in the oil, one of which is the viscosity index. In multi-viscosity oils, the left number refers to cold behavior of the particular oil, while the right number refers to its hot (100 degrees Celsius) behavior. So, for instance, 5W-30 oil would flow well when cold like 5-weight oil, but protect at high temperatures like 30-weight oil.

Do oils vary much by brand? Yes. The 5W-30 oil from one company might equal 10W-40 oil from another company in viscosity, because there might be a difference in some of the other properties of the oil, like its flash point (at what temperature it ignites). The numbers in multi-viscosity oil also don't tell anything about how viscous the oil is at normal engine operating temperatures, as opposed to extremes. The best advice here is to choose a familiar brand, and experiment with other major brands if you think it's too thin or too thick. Never mix brands or different weights. Wait until an oil change.

What about synthetics? Synthetics are better in every way, but they are much more expensive. They offer better high-temperature resistance and better low-temperature flow, and they leave nearly no deposits. Prices for synthetics are coming down, though, and there are also blends that combine synthetics with traditional mineral oils. Because synthetics flow and penetrate much better than regular oils, a change to synthetic oil will sometimes reveal leaks you didn't know existed.

Ratings. The American Petroleum Institute (API) assigns letter ratings to motor oil. The category ratings correspond to industry standards for various qualities like viscosity, thermal protection, and preventing deposits and sludge. Every few years, the currently awarded rating is changed. Currently, SL (Spark ignition, Category L) is the top rating. SJ was introduced in 2001 and SH in 1996.

As your car ages and becomes a high-mileage vehicle, many experts recommend that you change to thicker oil than is normally used. Over time, gaps between parts in the engine become larger, enabling less oil to reach critical parts. Ask a mechanic familiar with your model vehicle or ask the dealership if you should change the type of oil for your vehicle beyond 100,000 miles.

The underlying message is that all oil is not the same. Making sure you use the correct viscosity rating is just the start. The quality and characteristics of oils can vary greatly by brand, too.

What else you should know about Oil:

All synthetics are not equal. The API has not come out and defined what is "synthetic", but rather, classified oils into five major groups.

Group I base oils are the least refined of all of the groups. They are usually a mix of different hydrocarbon chains with little or no uniformity. While some automotive oils use these stocks, they are generally used in less demanding applications.

Group II base oils are common in mineral based motor oils. They have fair to good performance in the areas of volatility, oxidation stability, wear prevention and flash/fire points. They have only fair performance in areas such as pour point and cold crank viscosity. Group II base stocks are what the majority of engine oils are made from. 3000 mile oil changes are the norm.

Group III base oils are subjected to the highest level of refining of all the mineral oil stocks. Although not chemically engineered, they offer improved performance in a wide range of areas as well as good molecular uniformity and stability. By definition they are considered a synthesized material and can be used in the production of synthetic and semi-synthetic lubricants. Group III is used in the vast majority of full synthetics or synthetic blends. They are superior to group I and II oils but still have limitations. Some formulations are designed for extended oil changes. Amsoil XM Oils, Castrol Syntec and many others fall into this category.

Group IV are polyalphaolefins (PAO) which are a chemically engineered synthesized basestocks. PAOs offer excellent stability, molecular uniformity and performance over a wide range of lubricating properties. Amsoil Synthetics and Mobil 1 primarily use group IV basestocks. PAO is a much more expensive basestock than the highly refined petroleum oil basestock of Group III. (Can you say profit margin! Grab your ankles and sing along!)

Group V base oils are also chemically engineered stocks that do not fall into any of the categories previously mentioned. Typical examples of group V stocks are Esters, polyglycols and silicone. Redline uses an ester basestock.

In the 90s, Mobil filed suit against Castrol for falsely advertising Syntec oil as synthetic, when in fact it contained a Group III, highly hydroprocessed mineral (Dino) oil, instead of a chemically synthesized (group IV or V) basestock. Due to the amount that the mineral oil had been chemically changed, the judge decided in Castrol's favor. As a result, any oil containing this highly hydroprocessed mineral (Dino) oil (currently called Group III basestock by the American Petroleum Institute) can be marketed as a synthetic oil. Since the original synthetic basestock (polyalphaolefin or PAO) is much more expensive than the Group III basestock, most of the oil blenders switched to the Group III basestock, which significantly increased their profit margins.


What Oil do you use?

[Stormin]

Dang JC did you type all that ! Must have been up all night !!!!

Mobil 1 here.

[pontiaddict]

I have been using Royal Purple in all of my Pontiac engines and tranny's converters etc. I recommend it whole heartedly to all. They offer a complete line including the best water wetter out there Purple Ice.
This change in oil is a serious matter if you want your new engine to have any longevity you must consider this information.!

[Skippy]

Originally Posted by pontiaddict

I have been using Royal Purple in all of my Pontiac engines and tranny's converters etc. I recommend it whole heartedly to all. They offer a complete line including the best water wetter out there Purple Ice.
This change in oil is a serious matter if you want your new engine to have any longevity you must consider this information.!

I LOVE Royal Purple I used it on my car right before my road trip to: Tenessee, then to New York, then to Ottawa, Ontario, then another 5-6 hours North of that, then back down to Ottawa, from Ottawa, to Albany, New York. From Albany, back to Ottawa, from Ottawa to Syracuse, New York, then home.

After ALL of that, and all of my city driving I did while I was there, my change oil light came on in Georgia on the way home!

I have an extra quart in my trunk from the road trip, and when it comes time to change it I will be buying it again.

[~JC~]

Originally Posted by Stormin

Dang JC did you type all that ! Must have been up all night !!!!

Mobil 1 here.

Ahhh, Yea right! The wonders of Copy & paste are truley amazing

In the begining when the car was new and there was that breakin period I used regular Dino oil. Chaged the first batch at a 1000 miles, then again at 2500. Once it came the cars 3rd oil change 5000, I went to Mobile 1... I've since switched to Amsoil in light of Mobile 1 changing its formula from a true synth, to a blend synth... Mobile 1 still advertises it as fully synth but its not... After their law suit was lost against their competors using blend formulas and they still being able to call theirs synth when in fact it was not. It's only natural that Mobile switched to do the same thing but didn't lower their price... Can you say profits?

Not saying anything negative about Mobile 1, its a very nice oil but there are others that do much better such as Royal Purple, Red Line and Amsoil, (Not Amsoil XM) which are both TRUE Synth. And if I was in a situation were those oils were not available I'd use Mobile 1...

[FBodyPerformer]

If I could afford it, Id be running nothing but Amsoil. But my car doesnt even need it. When it does get to that point though, thats all that will go into it. Even over Royal Purple anyday!

I try to stick to only Mobile 1. When I dont wanna do the money, I get valvoline from work. Winter time its 5-30w and summer its 10-30w.

[~JC~]

Originally Posted by FBodyPerformer

If I could afford it, Id be running nothing but Amsoil. But my car doesnt even need it. When it does get to that point though, thats all that will go into it. Even over Royal Purple anyday!

I try to stick to only Mobile 1. When I dont wanna do the money, I get valvoline from work. Winter time its 5-30w and summer its 10-30w.

Unless you drive up north you really don't need the 5 the 10 will work just fine year round down here.

When it does get to that point though, thats all that will go into it.

Actually if your car gets to that point what you will need isn't a Synthethic but Dino oil... As time goes by the clerance between two points gets larger. What you want is to reduce that wear from the begining or at least after the breakin period of an engine or any other part for that matter that uses a lubicrant... As an engine ages it's bearings wear (that's what they are meant to do) You want to minimize this aging process but there is no stoping it.

In all honesty "Dino" oil is just fine if you change it at 3 months or every 3000 miles. There is no improvement to speak of in "Oil Analysis" between "Dino" and "Synthetic" when you follow the proceeding guide. However, synthetics tend to run cooler and lack the breakdown characteristics of dino oil. Nevertheless, if your like me were the car sees more time setting than running then 3 months could pass easliy by and the car never been driven more than 100 miles. That's not very affordable even with the cheapest oil and it isn't much fun changing the oil everytime you decide to drag the car out for a drive ... So it only makes natural sense to use a synthetic in my case.

Needless to say both types of oil can get contaminated and that's were a quality fiberglass filter plays a major role... If your going to go the more affordable route on oil don't be cheap with the filter. Since most filters out there are of the paper type element. These are the ones you want to steer clear of... Also another little know fact is that nearly all oil filters are produced by the "Wix Corporation." Sure name brands specifi a set of guidelines with which they want their filter to be constructed and some are of better quality than others but a paper filter is just that, a paper filter of any name...

K&N & Donaldson oil filters are two I can think of that have fiberglass elements... Can't say I'm a big fan of K&N air filters but their oil filters are a different story.

[1BADBIRD]

I've been using Mobil 1 5w-30 since I got the car, right after the regular oil break in period of course. I even use the Mobil 1 oil filter.

[Stormin]

never heard of " Royal Purple" ?? Is it available at Dicount or Advance ?

[Stormin]

Use Amsoil in the truck always.