Oil marketers will begin selling the new API SN/ILSAC GF-5 service category engine oil, a new specification that supersedes SM and GF-4, in October 2010.
The required phosphorous (P) concentration, which is representative of the anti-wear additive zinc diaklydithiophosphate (ZDDP) is unchanged relative to SM at .06% (600 ppm) minimum and .08% (800 ppm) maximum.
New car manufacturers will require SN/GF-5 for warranty coverage on 2011 model gasoline engine vehicles
There are no changes to the most current C-category specification, CJ-4, however, the latest information I have found lists the maximum P concentration as 1200 ppm (0.12%). I quoted 1100 in my engine oil article published in The Corvette Restorer. The following page (owned by API) has all the CJ-4 specs:
Given that CJ-4 allows approximately 50 percent more P concentration than SN or SM, it remains the best choice for vintage engines with sliding surface valve trains.
If you want to read all the details of the new SN category:
Duke
P. S. API has updated their "Engine Oil Guide" to reflect the elimination of several older service categories that are now "obsolete". Use of an obsolete classification is a violation of the API licensing agreement.
The required phosphorous (P) concentration, which is representative of the anti-wear additive zinc diaklydithiophosphate (ZDDP) is unchanged relative to SM at .06% (600 ppm) minimum and .08% (800 ppm) maximum.
New car manufacturers will require SN/GF-5 for warranty coverage on 2011 model gasoline engine vehicles
There are no changes to the most current C-category specification, CJ-4, however, the latest information I have found lists the maximum P concentration as 1200 ppm (0.12%). I quoted 1100 in my engine oil article published in The Corvette Restorer. The following page (owned by API) has all the CJ-4 specs:
Given that CJ-4 allows approximately 50 percent more P concentration than SN or SM, it remains the best choice for vintage engines with sliding surface valve trains.
If you want to read all the details of the new SN category:
Duke
P. S. API has updated their "Engine Oil Guide" to reflect the elimination of several older service categories that are now "obsolete". Use of an obsolete classification is a violation of the API licensing agreement.