in short, there are three types of "synthetic". group v, ester based,
group iv, olefin based, and group iii, highly refined mineral oils.
most modern "synthetics" are group iii, the others being much too
expensive. and utterly irrelevant if they're not properly used, i.e.
discarded after only 4500 miles!
On Sun, 18 May 2008 08:34:53 -0700, jim beam wrote:
How is that 'irrelevant'? Should we wait until the oil is thoroughly
contaminated before changing it?
For the life of me, I can't see how changing the oil 500 miles early
'damages' anything. Please explain this.
how do you /know/???? [rhetorical] you don't do analysis!
bottom line, color has nothing to do with it - the oil's filtered. any
particle, and it's only soot that makes it black, that can get through
the filter is too small to make any difference to lubrication. check
how thick the hydrodynamic oil films are, then look at the filter's
particle size pass-through.
On Fri, 16 May 2008 08:03:11 -0400, Elmo P. Shagnasty wrote:
Probably. They probably would have benefitted from people just changing
the oil in the first place. Most people that had these problems were the
people who changed the oil every 12,000 miles whether it needed it or not.
"I was once told informally by an oil company chemist that when the
catalyst which allows an oil to be multi weighted starts to break down, it
turns acidic and causes tarnish and other naughty things."
"A good lubricant must reduce particulate wear from the interaction of
Even the best lubricants degrade over time, as a result of friction and
chemical in the additive package reacting with particulate, moisture, heat
and oxygen resulting in acidic properties"
" At this point, the oil turns acidic, which is bad for moving parts."
Step 1 Change oil but not the filter. (Oil may turn acidic)"
There are plenty more.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.