Date: Thu, 25 Mar 1999 21:08:14 +0000
Reply-To: The Henrys <jch@VNET.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: The Henrys <jch@VNET.NET>
Subject: Re: Synthetic oil not worth it (long)
Content-Type: text/plain; charset=us-ascii
Hello all
Reading this thread of accounts of incidental accounts of experiences with oil
types, weights, and change intervals forced me to search my archives of the RX-7
list (we all have our mid-life crises). There was a reference there a couple
years ago to a copy written article from Consumer Reports.
"Motor Oils" Copyright 1996 by Consumers union of U.S., Inc., Yonkers,
NY 10703-1057. Reprinted and electronically posted to this mailing list
ONLY by permission from CONSUMER REPORTS, July 1996. Further
distribution, via print or electronic means, is strictly prohibited.
This was a pretty impressive taxi cab test over an extend period of time and
miles.
I guess one could find it in the RX-7 or Consumer Report Archives but in general
the conclusions were as follows:
Twenty oils were tested, nine were conventional 10W-30 oils, and eight
were 5W-30. Also tested were two synthetic oils, Mobil 1 and Pennzoil
Performax, and one synthetic-and-conventional blend, Valvoline
Dura-Blend; all three were 10W-30 oils.
No brand performed best! Brand didn't matter much as long as the
oil carried the industry's starburst symbol. Oils without the starburst may lack
the full
complement of additives needed to keep modern engines running reliably.
One distinction: According to the laboratory tests, Mobil 1 and Pennzoil
Performax synthetics flow better at low temperatures. They also have
the highest viscosity under high-temperature, high-stress conditions,
when a thick oil protects the engine. Thus, the article suggested that these
oils may be a good choice for hard driving in extreme temperatures.
Oil changes: How often?
The long-time mantra of Jiffy Lube has been to change your oil every 3000 miles.
Automakers recommend an oil change every 7500 miles (and a specific time
interval) for "normal" driving, and every 3000 miles for "severe" driving. Most
of us fall into one or more of those "severe" categories.
In our survey, almost two thirds of our readers said they had their oil changed
every 3000 miles or less. They may be following the thinking expressed by one of
our staffers: "I have my oil changed every 3000 miles because that's what my
father did, and all his cars lasted for many years."
To determine whether frequent oil changes really help, they changed the oil in
three cabs every 3000 miles, using Pennzoil 10W-30. After 60,000 miles, those
engines were compared with the engines from the base tests of the same oil,
changed every 6000 miles. No meaningful differences.
Determining whether synthetic oils last longer than conventional ones was a
separate test project. Mobil 1 synthetic in three cabs and changed every 12,000
miles. The results of these tests with those from the three taxicabs with Mobil
1 changed every 6000 miles. Unfortunately, two of the three engines using the
12,000-mile interval developed problems not attributed to the oil. The third
engine fared no worse than the three with 6000-mile intervals.
The bottom line?
Even in the severe driving conditions that a New York City taxi endures, no
benefit from changing the oil every 3000 miles rather than every 6000. The
"normal" service category should only require changing the oil every 7500 miles
(or at the automaker's suggested intervals) They did recommend changing the oil
filter with each oil change.
They did recommend not leaving any oil, synthetic or regular, in an engine for
12,000 miles, because accumulating contaminants ---- solids, acids, fuel, and
water ---- could eventually harm the engine.
This article was the first time I had see a reasonably quantitative examination
of any of the urban myths surrounding our oil changing habits. And with all this
said, I change the oil in all of my vehicles as close to 3000 miles as I can,
and my '84 Westy with 108K miles is the second lowest in the parking lot I call
my driveway, 2 over 200K, 2 over 180K and my wife's car (55k).
Hope this was not too long.
Jim Henry
Durham, NC
Kevin Sullivan wrote:
> Hallelujah! Somebody finally said it. (thanks, David)
>
> As my mechanic has told me for the last 5 or so years,
> changing the oil often in a gasoline engine is the single best
> thing you can do to clean and prolong the life of it. Synthetics
> are superior, but if you're changing it and the filter out every 3,000
> miles, the dino stuff will never have a chance to break down unless
> you're continually driving in extreme conditions.
>
> He also says buying any name brand $.99 / qt. that meets
> all of the guv'ment requirements will work just fine.
>
> Kevin
>
> From: David Marshall <vanagon@VOLKSWAGEN.ORG>
>
> >Here is my $0.02 worth on the subject:
> >
> >I think synthetic oil is great stuff and it is superior to dinosaur oil.
> >But, a lot of the manufactures tell you that you do not have to change it
> >as frequently as it doesn't break down as fast as dino oil. The fact is
> >that synthetic still gets as dirty as dino so you have to change it as
> >frequently as dino oil in my opinion. Personally I do not run synthetic in
> >any of my 5 VWs as it is just too expensive to justify the small amount of
> >extra protection that I will get. Chances are very good that your
> >wasserboxer will die from a non-oil related problem anyhow. In the winter
> >when it is anywhere from -10 to -40 I use 10w40 and in the summer I use
> >20w50. I use Castrol oil as they sponsor Volkswagen and Audi drivers in
> >their racing efforts. I change my oil every 5000km and change the filter
> >at the same time. Another thing to remember is there is no true Dino oil
> >anymore, all of them have Synthetic additives for extra protection.
> >
