ACEA A3 versus A5

[moribundman]

No.

A3-rated oil affords better engine protection than A5-rated oil. Just because A5 is newer doesn't mean it's better - at least not for engines that were designed for A3 oil.

 

[TheFuror]

quote:

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Originally posted by moribundman:
No.

A3-rated oil affords better engine protection than A5-rated oil. Just because A5 is newer doesn't mean it's better - at least not for engines that were designed for A3 oil.

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How does one find out which rating their engine needs?

The only thing my owners manual states (Chevy Avalanche) is to use an oil rated to GM's 6094M standard (low temp pumpability).

Thanx

Bob W.

 

[Matt89]

quote:

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A3-rated oil affords better engine protection than A5-rated oil.

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Is this another way of saying 'thicker is better'? I don't say this to be a smarta$$...

 

[williar]

The difference between A3 & A5 specs is the HT/HS rating. A5 has a HTHS of 2.9 to 3.5 mPa.s (low friction, low viscosity). A3 has a HTHS > 3.5 mPa.s. So while the difference between A3 & A5 isn't strictly viscosity, it's related to it.

 

[moribundman]

quote:

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How does one find out which rating their engine needs?

The only thing my owners manual states (Chevy Avalanche) is to use an oil rated to GM's 6094M standard (low temp pumpability).

Thanx

Bob W.

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There may well be factors other than HTHS that have to do with one oil being A3-rated and another one being A5-rated. However, the HTHS is important when it comes to wear, and I would not choose an oil that does not meet the minumum specs required for a particular motor.

Found the following here: http://www.imakenews.com/flashpoint/e_article000098450.cfm

quote:

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GM Reactivates Engine Oil Spec

Addressing attendees at ILMA’s Annual Meeting in Colorado Springs on Monday, representatives from General Motors (GM) announced that the automaker is reactivating its 6094M engine oil specification, beginning with 2004 model year vehicles. The specification had been mothballed when the American Petroleum Institute (API) established its “Starburst” program. GM said that the reactivation of 6094M was not tied to the delay in the issuance of the new GF-4 passenger car motor oil specification.

GM told the ILMA Annual Meeting attendees that owner’s manuals beginning with the 2004 model year would require that the engine oils meet the 6094M specification and have the API Starburst.

According to GM, 6094M is the same as the GF-3 performance specification, except for the maximum allowable low-temperature pumping viscosity. Under 6094M, the limits would be: 0W - 30,000 cP@ -40°C; 5W – 40,000 cP@ -35°C; 10W – 50,000 cP@ -30°C.

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[TheFuror]

quote:

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Originally posted by moribundman:
I would not choose an oil that does not meet the minumum specs required for a particular motor.

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How does one find out which oil, i.e., A3 or A5, is the one suited to the motor?

Thanx

Bob W.

 

[TomJones76]

quote:

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Originally posted by TheFuror:

quote:

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Originally posted by moribundman:
I would not choose an oil that does not meet the minumum specs required for a particular motor.

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How does one find out which oil, i.e., A3 or A5, is the one suited to the motor?

Thanx

Bob W.

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Check the owner's manual. You'll note that most cars that reference A1, A3, A5, etc will probably be European.
Actually, I can't think of an American or Japanese car I've ever heard of demanding an ACEA grade such as A1, A3, A5, etc.

 

[moribundman]

I guess the manual only states the required GM oil spec. Maybe GM technical support can tell you more about your oil choices. Ask them for a list of suitable oils, then check the data/spec sheets for each oil and see if they mention ACEA ratings. They often do.
If that particular engine is also available in any Euro GM (They do sell Pontiac, Chevy, and have of course Opel, Saab, etc) product, you may want to check what oil they use in Europe. Still, there may be differences, even if the basic engines are the same here and there.

[ September 03, 2004, 05:43 PM: Message edited by: moribundman ]

 

[TomJones76]

As a follow-up, you can find a healthy amount of information about the various ACEA grades at the below URL:
http://www.acea.be/ACEA/20020618PublicationsOilSequences.pdf
[WARNING! Big stinking PDF file!]

That will let you know the different between A3, B3 and E3, for instance.

 

[Audi Junkie]

My understanding is that they must pass the same long-life tests, just the HT/HS range is different. If your manual/situation calls for a light oil, A5... if the engine wants a thicker oil, A3. Either rating is a good oil. Saab oil is A5 and a killer product.

 

[TheFuror]

I have seen a number of posts that say folks will not consider an oil that doesn't meet ACEA A3 standards.

But, if an oil meets the A5 standards, don't you get the same "high performance" rating along with the fuel effeciency benefit?

Thanx

Bob W.