Team.
<Flame suit on>
Longer term contributors to this list will possibly be a little jaded
by the cyclic reworking of the oil debate over the last few years.
The basic query appears to arise from the concern that 'modern' oil
may only be suitable for modern engines, and therefore not suitable
for our older technologies.
The discussions and debates often became deeply technical and wandered
off into discussions about various additional additives that could
supplement the modern cocktail available from the big names out there.
I learned, from the feedback on this list, that the levels of ZDDP
additive in motor oil has been reducing over the years as it is
detrimental to catalytic converters. Unfortunately this reduction is
in turn detrimental to the life of camshafts that use flat face
followers (tappets) - that's us!!
<Wikipedia quote>
The latest API Service Standard designation is SM for gasoline
automobile and light-truck engines. The SM standard refers to a group
of laboratory and engine tests, including the latest series for
control of high-temperature deposits. Current API service categories
include SM, SL and SJ for gasoline engines. All previous service
designations are obsolete, although motorcycle oils commonly still use
the SF/SG standard.
<end quote>
The API Service Standard is an alphabetic progression, starting at SA
and currently at SM. In the SG standard, ZDDP at 1200-1300ppm was
incorporated. From SG and beyond this density has been steadily
reduced until today where SM has just 600ppm.
My simple rule of thumb therefore is to use whatever motor oil is
available that has an API no later than SG and change it every year.
No matter what the marketing guys might say if the container says API
SM don't use it.
That should spark up some input - %^)
--
_________________________________________
(______________ Alan Bromfield_______________)
(_______\____1957-BN4____/________)
(__tinyurl.com/healeyforum _)
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