Why do car oil specs keep changing?

[edwardh1]

the Sm label whatever thats called? I have a hard time believeing there are that many changes in the engines to have api or whoever mandate a new "rating"- is this all hype??
Are are the changes real changes or just enhancements like a 1% change causing an all new spec listing? There were probably a lot of changes in the 70 with emissions but you would thing that would have slowed down

 

[StevieC]

Without change there would be no advancement in technology, both in oil technology and engine technology!

Although some people on here truly believe it's nothing but a ploy to get old clunkers off the road which happen to be more reliant on certain oil additives like ZDDP.

 

[Ken2]

The auto makers want oil that provides longer oil drain intervals for less frequent published maintenance requirements,* fewer internal engine deposits, less engine wear, and low oil cost. Both the EPA and the car makers want better fuel mileage. This IS happening. Each new oil spec has tougher requirements for all the items above.


*The stealerships want more frequent maintenance visits so they lie about the requirements.

 

[edwardh1]

yes but what is the percentage improvement?? Curious.

 

[Pablo]

Good place to start: http://www.api.org/

 

[Mustang2008Z]

The new GF-5 Ratings will continue to have some GF-4 Specs, except, there will be changes for the catalytic converter, more protection for the engine, and more protection for the cars that run E-85 ethanol fuels, otherwise the engines will rust from the inside out on E-85 fuel under GF-4 ratings.

 

[Mustang2008Z]

Look for GF-5 Specifications as you search the web. Lubrizol is the sponsor of the website that gives a spiderweb type of comparison between GF-4 of today, and GF-5 of 2010.