Originally Posted By: moontan
update as in sn api rating...less phosphorus for catalyst equipped bikes.
Less phosphorus doesn't mean more wear... the more phos means it takes longer to be depleted so it only affects OCI not wear...
Quote 540 Rat
. If you’ve read Section 1 – Motor Oil “Wear Protection” Ranking List,
of this Blog, you know that the amount of zinc/phos, does NOT
determine an oil’s wear protection capability. Because it is
physically impossible for more zinc/phos to provide more wear
protection. Zinc/phos does NOT work that way. More zinc/phos simply
takes longer to become depleted, since there was more to begin with.
It is much like the way more gas in your tank will take longer to run
out, but more gas in your tank will NOT make more power.
But, many people incorrectly believe you need high levels of zinc/phos
for adequate wear protection in High Performance engines, simply
because they have always been told that, read that or heard that.
Amazingly, they’ve blindly accepted that notion with NO PROOF what so
ever. And unfortunately for them, that line of thinking is nothing
more than an old wives’ tale MYTH that took on a life of its own,
because it kept being repeated over and over for years and years. But,
repeating wrong folklore over and over, does NOT make it magically
become true. Engineering tests have BUSTED that old high zinc/phos myth.
Phosphorus limit set in 1993 and revised in 1996...
SH - Introduced 1993 has same engine tests as SG, but includes
phosphorus limit 0.12%, together with control of foam, volatility and
shear stability.
SJ - Introduced 1996 has the same engine tests as SG/SH, but
phosphorus limit 0.10% together with variation on volatility limits
SL - Introduced 2001, all new engine tests reflective of modern engine
designs meeting current emissions standards
SM - Introduced November 2004, improved oxidation resistance, deposit
protection and wear protection, also better low temperature
performance over the life of the oil compared to previous categories.
SN - Introduced in October 2010 for 2011 and older vehicles, designed to
provide improved high temperature deposit protection for pistons, more
stringent sludge control, and seal compatibility. API SN with Resource
Conserving matches ILSAC GF-5 by combining API SN performance with
improved fuel economy, turbocharger protection, emission control
system compatibility, and protection of engines operating on
ethanol-containing fuels up to E85.