<VV> A slightly corrected part 2

[Dale Dewald]

At 07:28 9/20/2008 -0400, Bob Helt wrote:
>OVERLAPPING  RATINGS  (E.g. SJ/SM or  CI-4/SL)
>Here is where the confusion begins. Let?s look at some examples. Consider  an
>SM rated 10W-30 oil (or 5W-20 too). Here we have conflicting specs. 10W-30 is
>  a GF-4 oil with reduced phosphorous but SM has no upper limit. So the GF-4
>spec  takes precedence and establishes the upper limit of 800 ppm. (The SM 
>spec
>upper  limit is simply any amount greater than 600 ppm.) Thus, this amount of
>  phosphorous (anything over 600 ppm) meets the SM spec.
>Now  consider a 20W-50 oil with an SJ/SM rating in the donut. SJ has an upper
>phos.  limit of 1000 ppm and SM has no upper limit. So this oil will have a
>maximum  phos. Of 1000 ppm. But what if this were a 0W-20 oil with these
>ratings? It  would require that the GF-4 spec be met with an upper limit 
>of 800 ppm
>phos.  despite the SJ/SM ratings.

Let's see if I understand this correctly; It would seem that the API 
specifications for SJ, SL and SM all allow a reasonable upper limit (1000 
ppm) of phosphorous (ZDDP?) in motor oils, likewise the diesel 
specifications up through CI-4 allow the same, if not more.

The specification that puts significant limits on P is the new GF-4 for 
lighter viscosity oils. I am of the understanding that not all lighter 
viscosity oils currently sold necessarily meet the GF-4 rating.  Therefore, 
the trick is to find 5W-30 or 10W-30 oils that do not meet the GF-4 
specifications.  Typically these will be marketed for diesel and older 
gasoline engines, but are usually rated CI-4/SL and have a 1000ppm limit.

What we would really like to see is an SM specification oil which would 
allow 1400ppm or more P in a10W-30 weight but which does not meet GF-4 
specifications (maybe this is not permitted).

Aren't EPA regulations (that started all this confusion in the first place) 
grand?

Dale Dewald
Hancock, MI

BTW, I use Amsoil synthetic type ACD 10W-30/SAE 30 HD Diesel Oil (API 
CI-4+/SL, no GF-4) in all of our Corvairs.  I change it once a year or 5000 
miles, whichever comes first.