From: chucko@kronos.arc.nasa.gov (Chuck Fry)
Subject: Motor oil is motor oil... or is it?
Summary: Don't believe the hype.  Look for the facts.
Organization: Recom Technologies, NASA Ames Research Center, Moffett Field, CA
Distribution: na
Date: Wed, 9 Sep 1992 23:49:02 GMT

At first I was amused by the "Brand X oil is better than Brand Y,
isn't it?" postings.  Now I'm irritated enough to have to post this.
Apparently a lot of people out there believe the bullshit they see in
the TV ads.

It's hard to get the facts when comparing brand name oils.  About the
only things you can honestly compare are prices, viscosity grades, and
API ratings (SG, CC, etc.) -- the latter are all the same anyway.  API
grade SG is the current MINIMUM standard for motor oils.  Sadly, there
are no tougher standards.

You aren't going to see real comparisons between the major brands.
You will hear people say what brand they think is best, but unless
they have a dynamometer and an engine shop at their disposal, you
can't trust their opinions.  I doubt that many of us here meet that
requirement.

So until someone who does can speak up, here's what I can tell you for
sure about motor oils.  Behind each of the facts is a couple of
fallacies waiting to trip you.

FACT: Synthetic oils really are better than petroleum-based oils.
They flow better at low temperatures, reduce friction, better protect
against wear, and withstand heat better because the molecules are
specifically designed for the application.

FALLACY: You can't run much longer oil change intervals with
synthetics, because the contamination builds up at the same rate
regardless of oil type or brand.

MY OPINION: Most anyone who changes their oil every 3K miles or 3
months tends to get long engine life, whether it's dinosaur oil or
synthetic.  I would say that changing oil frequently is much more
important than using The Right Brand.  If synthetic oil costs 3x what
dinosaur oil does, and price is an issue for you, change dinosaur oil
frequently.  If you can afford to change synthetics every 3K, do it!


FACT: Racing is one place where oil performance makes a difference.
The right oil makes more power and keeps the engine together longer.

FALLACY #1: Racing conditions aren't even close to what your mother's
grocery-getter sees; what works on the track won't necessarily work on
the street.  In particular, racers change oil after every event, so
they don't have to deal with as much contamination as street cars.

FALLACY #2: Race teams have been known to put another brand of oil in
their sponsor's bottles.  I have witnesses.

MY OPINION: Any major brand of synthetic racing oil will work well --
in a race car.  How it works on the street is another question
entirely.  The higher price of synthetic oil is a drop in the bucket
compared to the other costs in racing, and to its benefits.


FACT: There is a right grade of oil for every season and every engine.

FALLACY #1: Many performance buffs think thicker oil is always better.
They are wrong!  There is no reason to use 20W50 racing oil in an
engine designed for 10W30.  The extra viscosity costs you in power,
economy, and engine life.  It's better to go to an equivalent grade
synthetic oil.

FALLACY #2: There is such a thing as too cool; oil works best when it
is at least 180 degrees F.  Removing the thermostat, or using one
designed for too low a temperature, prevents the engine from reaching
the temperatures at which oil works best.  This again causes excess
friction, resulting in poorer power and economy, and more wear.

FALLACY #3: Thicker oil in an older engine is only a band-aid fix to a
problem that will require major surgery.  It restores oil pressure at
the gauge, but doesn't repair the bigger bearing clearances that
caused the low pressure in the first place.  Use it if you must, but
don't fool yourself that it's solved the problem.

MY OPINION: Ask your motor builder what grade is right for your
engine, and what temperature it should operate at.  Add an oil cooler
if it's running too hot.  Oil additives like "Motor Honey" are a waste
of money -- save the cash for a new engine (or car).


FACT: There are coatings which will reduce friction and extend
component life.

FALLACY: These coatings don't come in a can.  They have to be applied
to engine parts before the engine is assembled.

MY OPINION: Racers are taking advantage of coating technology.  It's
just a matter of time til the major car makers get around to it.


Hopefully this might clear the air a little bit.  Any motor builders
out there?  Let's hear the facts about what brands work best.

 -- Chuck Fry  Chucko@charon.arc.nasa.gov
Newsgroups: rec.autos.tech