by Robert Sanborn on Wed, Aug 16, 2006, who was a member of the STLE Society of Tribologists and Lubrication Engineers for 15 years.
Vehicle owners should be made aware that a new oil specification has been developed for the model year 2006 and newer. The reason for this change is that the Original Equipment Manufacturers (OEM) has changed their catalytic converters. This affects both gasoline and diesel engines. The specification for gasoline engines is GF-4 and diesels’ is CJ-4.** **The reason this is important to know is that motor oils and aftermarket additives can damage these new catalytic converters. The new specification calls for severe limits on the amount of sulfur, phosphorus, and sulfated ash. These additives and their by products can cause serious damage to these new catalytic converters. For this reason, when purchasing a motor oil, you should make sure that the oil you purchase and install meets the correct specification. If it is approved to meet this specification—GF-4 or CJ-4 it will be listed on the bottle. The American Petroleum Institute (API) certifies motor oils, and they audit motor oils testing for compliance. Any oil not meeting these specifications could cause damage and you could be faced with an expensive repair.
Aftermarket additives can also cause damage if they do not meet the new specifications. SFR’s ProTecta Engine Treatment, Engine Oil Booster, SFR’s Gaszol and D-Sol contain no sulfur or phosphorus and meet the sulfated ash limits when added to a GF-4 or CJ-4 motor oil. You will find a label right on the ProTecta or SFR bottle that states the product is GF-4 or CJ-4 compatible.