Originally Posted By: Coprolite
Energy conserving is purely a comparison to an arbitrary reference oil. If the oil tested is deemed to have better mpg results than the reference oil in that grade, it can be considered Energy Conserving.
The API ratings have nothing to do with how they oils were manufactured.
While I am not aware of the exact properties, I would bet each grade would have max hths and 40/100 viscosity ratings to stay under in order to be considered energy conserving.
Energy Conserving and CI-4 PLUS Designations
The bottom of the donut tells whether the oil has energy conserving properties when compared with a reference oil in an engine test or if an oil meets CI-4 PLUS requirements.
The term only seems to apply to X/20 and X/30's and the car manufacturers say the following:
When your car manufacturer refers to it as "energy conserving oil", they are referring to the actual viscosity (5W-30) as being "energy conserving". In other words, they see 10W-30 or 10W-40 as being not energy conserving because it is thicker than 5W-30.
Oils labeled as "Energy Conserving" have passed the test that measures an oil's ability to conserve energy. Widespread use of engine oils with this designation should result in an overall saving of fuel in the vehicle fleet as a whole, but a particular vehicle operator may not experience a fuel savings as a result of using these oils.
Used in conjunction with the CI-4 category, the "CI-4 PLUS" designation identifies oils formulated to provide a higher level of protection against soot-related viscosity increase and viscosity loss due to shear in diesel engines.
Now for the real silly part, because it appears the term has yet to be fully defined:
SAE Standards for Works In Progress
WIP - Not available for purchase at this time.
Document Number: J1423
Project Number: Project Initiation: October 2005
Revision Number:
Title: Classification of Energy Conserving Engine Oil for Passenger Cars, Vans, Sport Utility Vehicles, and Light-Duty Trucks
Issuing Committee:
Fuels And Lubricants Tc 1 Engine Lubrication
Scope:
This SAE Standard was developed cooperatively by SAE, ASTM, and API to define and identify Energy Conserving engine oils for passenger cars, vans, sport utility vehicles, and light-duty (3856 kg [8500 LB] GVW or less) trucks.
Rationale:
The scope of the revision to this standard is to include the API SM Energy Conserving Category (ILSAC GF-4) and also the use of the ASTM Sequence VIBSJ test for API SJ (ILSAC GF-2). The revisions bring SAE J 1423 up to date on current classification of Energy Conserving oils for passenger cars, vans, sport utility vehicles, and light duty trucks.
Return to Works In Progress List
In other words it's viscosity related, but if a 5/30 is approved when a 5/40 was previously the approved oil they often increase the Moly in particular and balance the add pack by cutting the detergents.
