<VV> SL or SM oil in Corvair....

[Secular]

    BobHelt at aol.com  wrote:
    >>? the SM spec ACTUALLY has no maximum Phosphorous requirement
  ----

  The latest API SM standard for car oils calls for a zinc and phosphorus content 
  less than 0.08% to reduce sulfur, carbon monoxide, and hydrocarbon emissions. 
  As a result of this mandate, some motor oils now have as little as 0.05% zinc 
  and phosphorus.

  Source:

  http://www.356registry.org/tech/modern_oil_in_the_356.html

  ---

  The current API SM gasoline motor oil specification limits phosphorus to 
  a maximum of 0.085 percent. Sulfur is limited to a maximum of 0.50 
  percent for 0W-20/0W-30/5W-20/5W-30 and 0.70 percent 
  for 10W-30 viscosity categories.

  Source:

  http://www.streetrodderweb.com/tech/0803sr_modern_engine_oil/questions.html

  ---

  The current API standard is SM, and calls for 0.06-0.08% Zn and P

  http://www.chevelles.com/forums/showthread.php?t=178372

  ----

  With the introduction a couple of years ago of ILSAC specification GF-4 and
  API specification SM for gasoline-only engine oils, the amount of
  phosphorous in the oil had to be reduced to prolong the life of catalytic
  converters. Zinc-based anti-wear compounds, like ZDDP, which also contain
  phosphorous, were reduced as well. These zinc compounds work well to
  protect flat tappet engines from excessive wear, so the modern gasoline-only
  engine oils are not as effective in this regard as they once were.
  http://www.chevytalk.org/fusionbb/showtopic.php?tid/193821/

  -----

  I was gonna quote a few lines from chapter 10 of the book:
  Corvair Basics [Lubrication & Oil Change] wherein Keith OnChuck
  suggests the use of API? SL oil in Corvairs... hmmm, so much for 
  getting da facts correct... :) 

  Cheers,


  Tony I.