Friction Modifiers, less or more friction?

[friendly_jacek]

quote:

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Originally posted by Michael SR:
i have searched, as well as trying to keep up with the pertinent discussions, forgive me if this has been answered elsewhere.

i'm foggy on the issue of "friction-modified" starburst oils versus thicker oils without friction modifiers. put that way, it makes it sound as if the non-starburst oils result in more friction within the engine. (as opposed to higher internal friction just due to viscosity.)

why would high performance/race applications use thicker, non "friction-modified" oils if it resulted in higher friction?

does valvetrain wear more as a result?

why can't an oil be both thicker and friction-modified?

what are the long-term effects on engine wear in using one type over the other, for street, and then for racing?

one of the reasons i ask is because an oil's performance doesn't seem to be correlated to whether or not it is a starburst oil. another reason, terry's statement that schaeffer's 15w40 isn't a good choice for an LSx engine due to lack of friction modifiers. and more unusual comments i've read over the past year that doesn't seem to jive with what we see in UOAs.

confused...

thanks.

-michael

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Good question, looking forward for good answers. One thing I wanted to clarify is that starburst symbol only indicates ILSAC certification and is not necesserely associated with friction modifiers use.

http://www.quakerstate.com/pages/carcare/whattoknow.asp:
"Due to the fact that the ILSAC requirements include a fuel economy requirement, the ILSAC Starburst symbol will typically be found only on lighter viscosity grades of motor oil such as SAE 5W-20, SAE 5W-30 or SAE 10W-30. These viscosity grades are generally preferred for use in cars made by General Motors, Chrysler, and Ford. These grades are also favored by the Japanese automakers."

I personally would like to find out which oils have friction modifiers and which do not.

For example, 15W40 mobil super 1300 has some moly in it. Does it mean it is friction modified?

 

[rugerman1]

Science and Technology of Oils and Lubricant Additives » Interesting Articles » Friction Modification - More R&D

Science and Technology of Oils and Lubricant Additives » Interesting Articles » Friction Modification - Ongoing Research

Science and Technology of Oils and Lubricant Additives » Interesting Articles » Friction Reducers and AW Additives


Search member #59 with the key words and you'll be on track.

Mark

 

[c_rossman]

I think it depends on the application. Like Transmission oil is friction modified to increase friction. Motor oil on the other had is friction modified to decrease friction.

 

[Michael SR]

aha, i was searching in the wrong forum. thanks!

-michael

 

[Michael SR]

i have searched, as well as trying to keep up with the pertinent discussions, forgive me if this has been answered elsewhere.

i'm foggy on the issue of "friction-modified" starburst oils versus thicker oils without friction modifiers. put that way, it makes it sound as if the non-starburst oils result in more friction within the engine. (as opposed to higher internal friction just due to viscosity.)

why would high performance/race applications use thicker, non "friction-modified" oils if it resulted in higher friction?

does valvetrain wear more as a result?

why can't an oil be both thicker and friction-modified?

what are the long-term effects on engine wear in using one type over the other, for street, and then for racing?

one of the reasons i ask is because an oil's performance doesn't seem to be correlated to whether or not it is a starburst oil. another reason, terry's statement that schaeffer's 15w40 isn't a good choice for an LSx engine due to lack of friction modifiers. and more unusual comments i've read over the past year that doesn't seem to jive with what we see in UOAs.

confused...

thanks.

-michael