DF Sales&Marketing
Oil Tech Moderator
in part from an article written by john martin, engine builder magazine
auto manufacturers and lube oil marketers worked closely with the American petroleum institute (api), the American society for testing and materials (astm), and the society of automotive engineers (sae) to specify pcmos as well as they knew how.
Oils were developed by analyzing actual field failures and developing laboratory engine tests that would replicate the field failures. It seemed everyone worked closely together without much dissention in the ranks.
Enter the epa
then the environmental protection agency (epa) got involved in chemical regulations, and the game became more adversarial and political. You must first realize that the epa and most environmentalists couldn’t care less about our internal combustion engines..
The epa first flexed its muscles when north American passenger cars began utilizing catalytic converters in 1975 to reduce co and hc emissions. Some laboratory engine tests using oils highly over-dosed with zinc dithiophosphate (zdp or zddp) extreme pressure (ep) additives showed that the phosphorous tended to “glaze” over the face of the catalyst substrate slowly rendering it ineffective.
No field tests that I’m aware of ever corroborated these lab test findings, but the epa flexed its muscles anyway and pushed for new lube oil chemical restrictions to minimize phosphorous (therefore zdp) content. They’ve been on this bandwagon ever since, and no one in our federal government has ever successfully moderated their powers.
Oil in the ’80s
by the 1980s auto manufacturers began pushing for the specification of new oil performance categories in which they could guarantee improved fuel economy. This brought about the development of friction-modified passenger car oils.
Oil marketers and auto manufacturers now had two new performance issues to deal with. The api, the astm, and the sae began developing new oil performance categories as quickly as they could. But the process of defining oil performance deficiencies, developing laboratory engine tests, and achieving consensus among all involved is slow and methodical and it costs millions of dollars to develop a useful new specification.
By the late ’80s American auto manufacturers (aama) decided the oil industry either wasn’t moving rapidly enough or weren’t addressing some of their specific needs, so they formed their own trade association. They formed the new group called the International lubricants standardization and approval committee (ilsac) to make sure their needs were being addressed.
The traditional api approach defined general pcmo performance level categories labeled as api sg, sh, etc., up to the current api sn. Ilsac members from the alliance of automobile manufacturers, which included european auto manufacturers and the japanese auto manufacturers association (jama) specified new performance categories labeled as gf-1, gf-2, etc., up to the current gf-5.
Oil and oes do mix
after much debate, the auto manufacturers and the oil industry learned to coexist, and the paired specification system sl/gf-3) sm/gf-4, etc.) continued forward through five oil performance upgrades and considerable expense through 2011. These upgrades occur every four years, and there is no end in sight.
I’m not sure I, or anyone else for that matter understands why general motors decided to get into the lube oil licensing business around 2010. [editor note: does “follow the money” ring home?] But they developed their own set of pcmo performance specifications (dexos 1, etc.) and required oil marketers who met these specifications to pay them a licensing fee if they wished to use the dexos name on their products.
I know of at least one lube oil marketer who told GM to go pound salt.
Here are the facts you need to know to intelligently purchase pcmos. First, pay no attention to the marketing hype. Look for the api “donut” or the ilsac “starburst” symbols [or statement which reads it meets the specification - there are many lubricant companies who do not subscribe to the api, or ilsac, but still meet the guidelines and specifications; they are still inspected by the api “watchdogs” and held to task if they are sub-standard]. The only currently active api specifications are api sj, sl, sm, and sn. Only ilsac gf-5 is currently active. Ilsac gf-4 was obsoleted one year after gf-5 was introduced.
If a dexos label also appears, that’s good news for GM warranty protection, but I wouldn’t lose any sleep over it if it weren’t there. Dexos oils are not gaining much traction in the marketplace.
Currently look for api sn/gf-5 because that will provide the best fuel economy for your late model (post 2006) passenger cars without valve train modifications.
However, if you have an older engine design or you have altered the valve train (high lift cam, etc.), all bets are off!
There are a myriad of hot rod or racing oils which are out there, [along with a few high performance specialty oils, such as “swepco’s 306 supreme formula engine oil”, api sl/ci-4] Which have higher zddp levels to protect pushrod tips and flat tappet cams and lifters.
Although these oils are expensive, they are not nearly as expensive as a replacement cam and lifters.
when it comes to engine oil, the
more recent the specification, the
better the oil performance except
valve train wear and ep protection.
If your flat tappet camshaft isn’t very radical, or if you are utilizing rollers, you might take a second approach. Break the engine in on one of the many break-in-oils out there. This will coat the cam and lifter surfaces with the sacrificial zddp film the valve train needs for proper component protection. Then you can switch to a lower zddp oil (api sn/gf-5) to maximize vehicular fuel economy. You might need to use a hot rod/break-in/specialty oil periodically to replenish the zddp but the question remains as to when to do that.
This is not as safe an approach as is the use of specialty oils, because no one is certain how much zddp your valve train actually needs.
Carefully consider viscosity grades for late-model engine designs (e.g., ls engines, modular fords, etc.). Since most of them were designed for very low viscosity oils, they don’t like thick oils us old school, old racers are fond of. I know of several examples where both ls and modular engines have failed because of their inability to pump thicker oils through all the engine oil passages. Play safe and use an oil specifically designed for these new engine families.
auto manufacturers and lube oil marketers worked closely with the American petroleum institute (api), the American society for testing and materials (astm), and the society of automotive engineers (sae) to specify pcmos as well as they knew how.
Oils were developed by analyzing actual field failures and developing laboratory engine tests that would replicate the field failures. It seemed everyone worked closely together without much dissention in the ranks.
Enter the epa
then the environmental protection agency (epa) got involved in chemical regulations, and the game became more adversarial and political. You must first realize that the epa and most environmentalists couldn’t care less about our internal combustion engines..
The epa first flexed its muscles when north American passenger cars began utilizing catalytic converters in 1975 to reduce co and hc emissions. Some laboratory engine tests using oils highly over-dosed with zinc dithiophosphate (zdp or zddp) extreme pressure (ep) additives showed that the phosphorous tended to “glaze” over the face of the catalyst substrate slowly rendering it ineffective.
No field tests that I’m aware of ever corroborated these lab test findings, but the epa flexed its muscles anyway and pushed for new lube oil chemical restrictions to minimize phosphorous (therefore zdp) content. They’ve been on this bandwagon ever since, and no one in our federal government has ever successfully moderated their powers.
Oil in the ’80s
by the 1980s auto manufacturers began pushing for the specification of new oil performance categories in which they could guarantee improved fuel economy. This brought about the development of friction-modified passenger car oils.
Oil marketers and auto manufacturers now had two new performance issues to deal with. The api, the astm, and the sae began developing new oil performance categories as quickly as they could. But the process of defining oil performance deficiencies, developing laboratory engine tests, and achieving consensus among all involved is slow and methodical and it costs millions of dollars to develop a useful new specification.
By the late ’80s American auto manufacturers (aama) decided the oil industry either wasn’t moving rapidly enough or weren’t addressing some of their specific needs, so they formed their own trade association. They formed the new group called the International lubricants standardization and approval committee (ilsac) to make sure their needs were being addressed.
The traditional api approach defined general pcmo performance level categories labeled as api sg, sh, etc., up to the current api sn. Ilsac members from the alliance of automobile manufacturers, which included european auto manufacturers and the japanese auto manufacturers association (jama) specified new performance categories labeled as gf-1, gf-2, etc., up to the current gf-5.
Oil and oes do mix
after much debate, the auto manufacturers and the oil industry learned to coexist, and the paired specification system sl/gf-3) sm/gf-4, etc.) continued forward through five oil performance upgrades and considerable expense through 2011. These upgrades occur every four years, and there is no end in sight.
I’m not sure I, or anyone else for that matter understands why general motors decided to get into the lube oil licensing business around 2010. [editor note: does “follow the money” ring home?] But they developed their own set of pcmo performance specifications (dexos 1, etc.) and required oil marketers who met these specifications to pay them a licensing fee if they wished to use the dexos name on their products.
I know of at least one lube oil marketer who told GM to go pound salt.
Here are the facts you need to know to intelligently purchase pcmos. First, pay no attention to the marketing hype. Look for the api “donut” or the ilsac “starburst” symbols [or statement which reads it meets the specification - there are many lubricant companies who do not subscribe to the api, or ilsac, but still meet the guidelines and specifications; they are still inspected by the api “watchdogs” and held to task if they are sub-standard]. The only currently active api specifications are api sj, sl, sm, and sn. Only ilsac gf-5 is currently active. Ilsac gf-4 was obsoleted one year after gf-5 was introduced.
If a dexos label also appears, that’s good news for GM warranty protection, but I wouldn’t lose any sleep over it if it weren’t there. Dexos oils are not gaining much traction in the marketplace.
Currently look for api sn/gf-5 because that will provide the best fuel economy for your late model (post 2006) passenger cars without valve train modifications.
However, if you have an older engine design or you have altered the valve train (high lift cam, etc.), all bets are off!
There are a myriad of hot rod or racing oils which are out there, [along with a few high performance specialty oils, such as “swepco’s 306 supreme formula engine oil”, api sl/ci-4] Which have higher zddp levels to protect pushrod tips and flat tappet cams and lifters.
Although these oils are expensive, they are not nearly as expensive as a replacement cam and lifters.
when it comes to engine oil, the
more recent the specification, the
better the oil performance except
valve train wear and ep protection.
If your flat tappet camshaft isn’t very radical, or if you are utilizing rollers, you might take a second approach. Break the engine in on one of the many break-in-oils out there. This will coat the cam and lifter surfaces with the sacrificial zddp film the valve train needs for proper component protection. Then you can switch to a lower zddp oil (api sn/gf-5) to maximize vehicular fuel economy. You might need to use a hot rod/break-in/specialty oil periodically to replenish the zddp but the question remains as to when to do that.
This is not as safe an approach as is the use of specialty oils, because no one is certain how much zddp your valve train actually needs.
Carefully consider viscosity grades for late-model engine designs (e.g., ls engines, modular fords, etc.). Since most of them were designed for very low viscosity oils, they don’t like thick oils us old school, old racers are fond of. I know of several examples where both ls and modular engines have failed because of their inability to pump thicker oils through all the engine oil passages. Play safe and use an oil specifically designed for these new engine families.
