Date:         Thu, 20 Jun 1996 09:00:00 -0700 (PDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Maher, Steve (SD-MS)" <SMAHER@gi.com>
Subject:      Re: Consumer Reports on oil/L


>They felt that the test wasn't sufficient to measure sludge buildup, as
>this requires the engines to sit cold and cabs never sit for long.

Remember, too, some very important points:

1.) When an engine "sits cold", sludge isn't the only thing that happens
to the oil. It also drains down into the crankcase, leaving little on
the moving/rubbing parts of the engine. So, when you start up "cold"
(i.e. engine has been sitting still for hours), you have very little oil
in the bearings, journals, etc. This is when you get the most wear, of
course, and is the principal test of oil-- which was by and large left
out of the COnsumer Reports tests.

2.) Consumer Reports did not test any aircooled cars. Well, they can't,
since nobody makes them any more, in numbers great enough to matter.
But for us luftboxers on the list, this is a very big deal, since
aircooled engines run hotter than their watercooled brethern. This
elevated temp has its greatest effect on-- you guessed it-- the oil.
It breaks down faster with high temperatures.

3.) Consumer Reports also did not test any 2-ton vehicles that were
being pushed by little 90-hp-or-less engines. We all know that Volksie
engines, particularly in heavier vans such as Westies, are working their
little tails off, much harder than your average Honda. They turn more
revs per mile, and wear out more quickly. One product of this, is more
metal particulates in the oil for every 1,000 miles. Hard-working
engines need their oil changed more often than "vanilla" cars.


Consumer Reports can't be blamed for points 2 and 3 above-- they are
trying to test cars that are fairly representative of the "average"
car that most people drive. It's not their fault that we listmembers
are weird. But we do have to take our own special circumstances into
account, and not blindly accept what CR said, as gospel.

As for Point 1... well, every now and then, the smart people at Consumer
Reports need vacations like the rest of us, and I think they took one
while this series was being planned. Taxi engines lead a hard life, no
doubt-- but they also lead a DIFFERENT life from your "average" car.
More miles between cold starts is the most significant. Also, most
taxis tend to be medium or large cars in this country-- when was the
last time you saw a Tercel or an Aspire with a meter flag?

Small cars tend to have small, high-revving engines nowadays-- sort
of like certain older German cars we all know and love. Some larger,
taxi-type cars also do, but many larger cars tend to have larger engines
with taller trannies that let them rev slower.

I skimmed over the CR article, and don't remember if they mentioned
exactly what makes and models they ran these tests on. Anybody know?

I usually have great respect for CR-- while not perfect, they are the
closest thing to a large, impartial analyst I've ever seen. But they
occasionally goof-- anyone recall the time they tested auto stereo
speakers? They mounted them all, one set at a time, in the doors of
the same Ford Granada, and then stated that all the speakers tested,
had a strange and annoying resonance around the pitch of G in the musical
scale, but made no attempt to guess why. Evidently none of their test
"engineers" was familiar with basic harmonics of cavities-- the property
that makes a bugle able to play certain notes but not others, or that
makes a Coke bottle hum at a certain pitch when you blow across it. If
they had tried installing the same speakers in car doors of different
size or depth, they would have found major differences. I have a hunch
that the Vacation Effect was at work on that one, too.

But most of CR's work is very valuable, if for no other reason than they
work hard to strip away any brand loyalties that otherwise cloud issues.
And this oil report is too-- the fact that it found little difference
between various dino oils is significant.

They also found that Slick-50 and STP oil treatment had no apparent
effect in their tests-- a sentiment I've heard a few times from various
listmembers here, too. But keep in mind that these additives' chief
claim to fame, is that they claim to leave more slippery stuff on engine
parts during long, cold shutdowns, than ordinary oil does. Again, cold-
shutdown performance was specifically NOT tested by CR, much. So the
jury's still out on this one, as far as CR's tests go.

Personally I feel that Slick-50 et.al. are snake oil. But it's mostly
a gut feel rather than something I can prove.

I like CR a lot, and will keep my subscription current. But comparing
taxis to VW buses, for our particular cases, is like apples and oranges.
I'll keep using generic dino oil (made by Valvoline) and changing it every
3,000, in all my cars.

Ciao,
 ______________________________________________________________________
           _                                            ______________
    ______//________    Steve Maher    smaher@gi.com   //__][__||____\\
   /o _   |  -| _   \   San Diego, CA     75461,1717  (o _-|       _ o|
   `-(_)=======(_)---'                                 '(_)-------(_)-'
 '66 Mustang Coupevertible      '89 Son Sherwin        '80 VW V6anagon

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