Re: Oil Stuff

["Meron" <phwomp@cosmoslink.net>]

1)  Does multi-vis therefore have NO advantages?  Since I doubt this 
is the case, what are the ones it does have?
The above question is rather complicated and I hesitate to come up with a
straight answer, let me just mention a few thoughts, even though nobody (on
a professional level) deny the fact that all oils lose the multi-vis
characteristics trait rather quickly, they (the oil companies) still claim
it!? and thechnically , they are making a false statement! 
Now if you ask "should I switch to single grade oil?" my answer is NO, and
the explanation is that a lot of research is going toward the multi
viscosity oils and at present time they are the most advanced on the market
( excluding industrial oils, a different world all together). 
I am apologizing for not being able to have a better definite answer. 

>(My understanding is that 
>synthetic is slower to lose volatile elements, and is more 
>stable in terms of lasting before it breaks down in viscosity.)
Your understanding is correct to some degree but not in relation to
viscosity..
First no oil lose its viscosity (viscosity: the properity of resistance to
flow in a liquid) it just changes....
The whole issue (for syntethic oils) is that synthetic oils are (basically)
a single grade, the SAE test (I think it's SAE but it might be ASTM) is not
applicable to synthetic oils, synthetic oils maintain their viscosity a lot
better that std. oils so you DON'T need a synthetic that is multi
viscosity, in the early days of synthetic oils it was mostly sold as a
single grade BUT since consumers are so conditioned to multi-visc. The oil
companies felt they had to classify their oils as a multi-visc. in order to
penetrate the consumer market. Again "multi-visc." makes no difference (or
extremely little) in relation to synthetic oils. If you try to pour (which
is more or less the viscosity test) 10W oil in, say, -20F it will pour like
80W in +70F (examples are estimates only) but if you pour 40W synthetic in
-20F it will pour like 50W in +70F, big difference!!!! 
The above is information related to me by Mobil chemical engineering
personal and corroborated by many tests professional and personal.
   

I hope the above helps,
with great respect to all our esteem list members,
Avi Meron
86 5Kcstq
I am not always the devil advocate but never one to miss an
opportunity.....