I can only find GM 4718M standard on 30 grade mobil1 oil, not even in the newest 0W40. What is GM 4718M really about? I also see many LS1(GM 4718M required) owners here using oil other than 30 grade, would it cause any problems to the engine?
What is GM 4718M about?
- Thread starter hungdynasty
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Castrol claims Syntec meets GM4718M in xW-40 and xW-50.
The GM 4718, or Corevette test, is not just a single test, but a series of tests as you would find in any engine oil specification.quote:
Originally posted by hungdynasty:
I can only find GM 4718M standard on 30 grade mobil1 oil, not even in the newest 0W40. What is GM 4718M really about? I also see many LS1(GM 4718M required) owners here using oil other than 30 grade, would it cause any problems to the engine?
I am told that this standard includes the physical chemical type tests, the bench tests, and the engine dynamometer tests. For example, this specification requires the oil to pass the Sequence IIIE engine test, the Sequence VE engine test, the High Temperature High Shear Viscosity at 150 C, Filterability, Distillation, Foaming, the Sequence VI engine test for Fuel Efficiency, has a Phosphorus maximum of 0.12%, and Flash Point.
Many oils advertise that they meet this test, including M1 5w-30 and 10w-10, Kendall GT-1 full synthetic in the same weights, as well as Syntec in those weights. I believe that GM is only concerned with 30 weight and not the 40 weights.
Bob W.
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=1;t=001047
http://www.mobil1.com/index.jsp
"06/10/2002 GM vs. ACEA Engine Oil Specs"
"I would like to know more about General Motors service fill specification GM 4718M. ...."
"The General Motors specification GM 4718M is an automobile engine oil service fill specification. General Motors also has a factory fill specification for automotive engine oils – 9985847. ..... The GM specification only meets the requirement of a single manufacturer, whereas the API and ACEA specifications meet the requirements of the entire region, including all manufacturers within it. Therefore, you will not likely see much information about any specific builder approval, unless the oil company has the initial fill business. ...."
Basically when the standard was adopted the Corvette required an oil that would resist high temperatures. Mobil 1 5W-30 was adopted as factory fill, and gradually other synthetics, and some non-synthetics, met the requirements.
I had a UOA done at 10,700 with Mobil 1 15/50 with great results, no problems so far using non specified oil.
Found this at a corvette site, their bottom line was use a syn 10/30 (NOT 5/30) and don't worry about the spec.
"Using information provided by the the GM Powertrain Division and the Lubrizol
Corporation, a chemical manufacturer that sells raw materials to the world-wide
oil refining industry, we researched these different oil specs.. GMPT supplied
the particulars of 4718M and Lubrizol's web site (www.lubrizol.com) had the
test sequence requirements for API SJ, ILSAC GF-2 and AECA 3-96.
SJ and GF-2 have only minor differences, none of which affect the ability of
oils meeting those specifications to lubricate. 4718M and 3-96 are similar,
however, both differ from API SJ and ILSAC GF-2 in two critical measures: 1)
the GM and the AECA standards require better performance in high
temperature/high shear environments, two conditions present in any engine
generating very high oil temperatures and 2) both 4718M and 3-96 require a
lower oxidation rate, also a necessity in an engine generating high oil
temperatures. Those differences mandate synthetic oil because petroleum-based
oils cannot meet the higher requirements. Better high temperature/high shear
numbers and lower oxidation rates are characteristic of all quality synthetic
oils."
"Using information provided by the the GM Powertrain Division and the Lubrizol
Corporation, a chemical manufacturer that sells raw materials to the world-wide
oil refining industry, we researched these different oil specs.. GMPT supplied
the particulars of 4718M and Lubrizol's web site (www.lubrizol.com) had the
test sequence requirements for API SJ, ILSAC GF-2 and AECA 3-96.
SJ and GF-2 have only minor differences, none of which affect the ability of
oils meeting those specifications to lubricate. 4718M and 3-96 are similar,
however, both differ from API SJ and ILSAC GF-2 in two critical measures: 1)
the GM and the AECA standards require better performance in high
temperature/high shear environments, two conditions present in any engine
generating very high oil temperatures and 2) both 4718M and 3-96 require a
lower oxidation rate, also a necessity in an engine generating high oil
temperatures. Those differences mandate synthetic oil because petroleum-based
oils cannot meet the higher requirements. Better high temperature/high shear
numbers and lower oxidation rates are characteristic of all quality synthetic
oils."
actually, they don't. it's advertising legalese.
the 5w-30 and 10w-30 say "exceeds GM4718M..."
the others say "exceeds engine protection requirements of GM4718M..."
which is a subset. (i'm not implying anything about an oil's suitability for the application. but i do wonder if this is technically in violation of warranty requirements.)
-michael
Nice catch, I shouldn't have missed that.
So Mickey you mean that all synthetics should have no problem in any GM 4718M required engine right? But I just wonder if you don't use GM 4718M oils, would it void the warranty from GM?
The bottles of 5w-30 and 10w-30 also claim this.
What concerns me about the new Syntec xw-30 is the borderline HT/HS rate (2.9).
Bob W.
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