Oil, What Does Gen Iii , Iv Mean

[tmastres]

Sorry to keep the oil debate going but we've been discussing it so long know I'm finally realizing how much I don't know. Anyhow I'm actually just looking for some clarification regarding the "gen III, IV " thing. What exactly does this refer to and how does it ralate to the oils we use? Thanks!

[mburnickas]

Sorry to keep the oil debate going but we've been discussing it so long know I'm finally realizing how much I don't know. Anyhow I'm actually just looking for some clarification regarding the "gen III, IV " thing. What exactly does this refer to and how does it ralate to the oils we use? Thanks!

See below for groups. AS far as what oil type you use, it depends on driving conditions and about 10 other things. If you do normal drains, non turbo etc etc any one will be fine. At one time I would fight tooth and nail and say this and that. The more I test etc , the more I feel YOU need to see what works for you. Each driver, motor, oil, envir etc is different.

This might helps:

Group I Solvent Freezing 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 on the market use Group I stocks, they are generally used in less demanding applications.

Group II Hydroprocessing and Refining Group II base oils are common in mineral-based motor oils currently available on the market. They have fair to good performance in lubricating properties such as volatility, oxidative stability and flash/fire points. They have only fair performance in areas such as pour point, cold crank viscosity and extreme pressure wear.

Group III Hydroprocessing and Refining Group III base oils are subjected to the highest level of mineral oil refining of the base oil groups. Although they are not chemically engineered, they offer good performance in a wide range of attributes as well as good molecular uniformity and stability. They are commonly mixed with additives and marketed as synthetic or semi-synthetic products. Group III base oil products have become more common in America during the past decade.

Group IV Chemical Reactions Group IV base oils are chemically engineered synthetic base stocks. Polyalphaolefins (PAOs) are a common example of a synthetic base stock. Synthetics, when combined with additives, offer excellent performance over a wide range of lubricating properties. They have very stable chemical compositions and highly uniform molecular chains. Group IV base oils are becoming more common in synthetic and synthetic-blend products for automotive and industrial applications.

Group V As Indicated Group V base oils are used primarily in the creation of oil additives. Esters and polyolesters are both common Group V base oils used in the formulation of oil additives. Group V oils exhibit a wide variety of properties specific to each individual oil's formulation. Group V base oils are generally not used as base oils themselves, but add beneficial properties to other base oils.

[TunedRX300]

Amsoil XL series' base stock is Group III. Other Amsoil oils are Group IV

German Castrol is Group IV PAOs

Mobil 1 used to be Group IV, now rumored to be Group III with some interesting discussions going on BITOG.

For 1mzfe, I would run only PAOs based oil for better oxidation resistance, after I use up my current stash of M1 5w-20, GC 0w-30 will get the nod. Just in case GC will use a Group III like everyone else in the future, Pennzoil Platinum (Group III) + Auto-RX is my plan C.

My Acura gets Amsoil 5w-20, j-series engine is bullet proof, group III with an good additive package is fine.

Base stock is only part of the equation, in-oil additives are also important to make a good oil.

[tmastres]

Thanks for the great info, much appreciated!!