Hi,
I can offer two bob's worth.................
Firstly the API was really an umbrella body of the Oil Industry and I doubt if much input was given from end users (OEMs)
Petrol lubricants
SA had a life until 1930 but SB had a life until 1951 - 22 years)
SC survived 16 years until 1967, SD for 4 years, and SE for 8 years. This shows that technical developments were slow and in my opinion the API just went along with it all!
Some OEMs such as Daimler-Benz maintained lists of approved lubricant. VW and Porsche recommended using HD (HDEO) lubricants
Technical and Emissions requirements started to have an impact!
Diesel lubricants
CA was valid until 1959, CB until 1961 and CC until 1990! CD, CD11 and CE survived until 1994. Some are still prescribed
In the 1950s many Diesel engine manufactures were using their own standards, CAT, Benz etc etc
By the late 1970s early 1980s US engine OEMs such as Cummins, Mack etc were suffering problems due to lubricant performance in their new engine families. The API introduced some Technical Committee structures to better meet the end user's needs. They were slow to react!!!
Euro OEMs were increasingly concerned too about the lack of coherent and meaningful Euro/International standards and in 1996 the CCMC European lubricant standards were taken on board by ACEA
With ACEA the OEMs set the standards and flagged up emerging trends! The Oil Industry participated and excellent specification protocols emerged
Have no doubt that when an OEM sets a specification it is not just to be different or exclusive - they have been well researched for their specific needs!!
It is clear that if an OEM has a specification but states for example a API SN or ACEA A3/B3 lubricant can be used - then it can be within any possible limitations set!
This post could have been much longer and in greater depth - I've just tried to touch on the facts
I can offer two bob's worth.................
Firstly the API was really an umbrella body of the Oil Industry and I doubt if much input was given from end users (OEMs)
Petrol lubricants
SA had a life until 1930 but SB had a life until 1951 - 22 years)
SC survived 16 years until 1967, SD for 4 years, and SE for 8 years. This shows that technical developments were slow and in my opinion the API just went along with it all!
Some OEMs such as Daimler-Benz maintained lists of approved lubricant. VW and Porsche recommended using HD (HDEO) lubricants
Technical and Emissions requirements started to have an impact!
Diesel lubricants
CA was valid until 1959, CB until 1961 and CC until 1990! CD, CD11 and CE survived until 1994. Some are still prescribed
In the 1950s many Diesel engine manufactures were using their own standards, CAT, Benz etc etc
By the late 1970s early 1980s US engine OEMs such as Cummins, Mack etc were suffering problems due to lubricant performance in their new engine families. The API introduced some Technical Committee structures to better meet the end user's needs. They were slow to react!!!
Euro OEMs were increasingly concerned too about the lack of coherent and meaningful Euro/International standards and in 1996 the CCMC European lubricant standards were taken on board by ACEA
With ACEA the OEMs set the standards and flagged up emerging trends! The Oil Industry participated and excellent specification protocols emerged
Have no doubt that when an OEM sets a specification it is not just to be different or exclusive - they have been well researched for their specific needs!!
It is clear that if an OEM has a specification but states for example a API SN or ACEA A3/B3 lubricant can be used - then it can be within any possible limitations set!
This post could have been much longer and in greater depth - I've just tried to touch on the facts
