Date: Wed, 19 Jul 2000 08:13:01 -8
Reply-To: Wes Neuenschwander <wesn@eskimo.com>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Wes Neuenschwander <wesn@eskimo.com>
Subject: Oil Viscosity Recommendations
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I'm trying to resolve some discrepancies between various sources of
information on recommended motor oil viscosities for different
temperature operating ranges for my '91 Westy.
According to the chart in my 91 Vanagon Volkswagon Owner's Manual
(p. 98), the following are the temperature ranges recommended for
various common single/multi-grade engine oils:
SAE 30 32 - 82 F
SAE 10W30 / 10W40 -5 - 60 F
SAE 15W30 / 15W40 5 - 95 F
SAE 20W30 / 20W40 15 - 95 F
(Please forgive any interpolation errors; it's a small chart and my eyes
aren't what they used to be.)
About 5 years ago however, my local VW Dealer/Service shop (Carter
VW in Seattle) starting using SAE 10W40 as their standard oil for
Vanagons. When I challenged the appropriateness of this choice
(average temps in this area, especially if you include Eastern
Washington, much more closely correspond to the 5F-95F range of the
15W40 oil) they responded that VW of America had revised their
recommended oil viscosity ranges and that 10W40 was now the
preferred viscosity for "our area". They have not been able to document
this however in spite of repeated requests (vague references to a service
bulletin that they never seem to be able to produce) and I'm getting a
little suspicious that this is a bunch of baloney.
So my question is: Does anyone have any information on such a
revised oil viscosity recommendation or know how I could contact
VWoA directly to confirm or deny this?
This issue recently came to a head while I was returning from an
extended trip though the upper midwest. While driving up a steep long
pass in Montana, with ambient temps ranging to 103F, my oil pressure
light and buzzer suddenly came on. I pulled over immediately, shut-off
the engine, and waited a few minutes before restarting the engine and
continuing over and down the pass - now holding my speed to 50-60
MPH. I immediately suspected the cause was too light an oil for these
driving conditions. Fortunately, the oil pressure light did not come on
again during the remainder of the trip (a few hundred miles more, with
temps down into the 80's and low 90's and continued reduced driving
speeds).
If too light an oil was the cause, I intend to complain to the dealer, since
I had advised them during the last oil change, just prior to the trip, that I
would be driving under such extreme conditions. While it appears no
permanent damage was done, it really ticks me off that they would so
peremptorily and recklessly use an oil that was way underated for the
conditions. If I can document that this VWoA revised recommendation
for 10W-40 oil is bogus, I intend to rub the Dealer's nose in their nasty
BS until they squirm and formally appologize. I also intend to serve
them notice of their potential liability for any damage that may have
resulted from their malfeasence, FWIW (probably personal satisfaction
only).
I appreciate any advice, as always.
-Wes
Wes Neuenschwander
Seattle, WA
wesn@eskimo.com