Date: Fri, 10 Oct 1997 00:46:18 UT
Reply-To: Tom Brunson <TABRUN@CLASSIC.MSN.COM>
Sender: Vanagon mailing list <Vanagon@Gerry.SDSC.EDU>
From: Tom Brunson <TABRUN@CLASSIC.MSN.COM>
Subject: Re: Synthetic Oil(s) (long)
While I'm not a CHEMICAL engineer, I've worked a lot on the mechanical side
selecting lubricants for a range of industrial products; and I've used
synthetics since the mid 70s in my cars. For a while I even got an Amsoil
dealer license so I could buy at dealer pricing; but have never sold the
stuff, so this isn't a sales pitch. However the monthly Amsoil dealer
newsletter has had a lot of semi-technical articles about oil properties and
what makes for a good "real-world" engine lubricant.
As mentioned in the referenced "snake oil" article Amsoil also dismissed the
miracle additives and the "drained all the oil" demos. When Castrol 5W50 first
came out they also cautioned that such a wide range may not be desirable - a
modern engine designed for 5W30 could find it too heavy when at temperature
and highway speed. (Yes, an oil can be too viscous and cause oil pressure to
be too high - opening bypass and relief valves and not going where it should.)
Good synthetic oils get a wide viscosity range from their base stock without
VI (viscosity improvers) additives which tend to break down with use. Good
synthetics show almost no viscosity change after extended use, while
conventional oils often thin-out, or sludge up as the VIs wear out. (The base
stock even of petroleum oils lasts - but need the additives to keep
lubricating well.)
Synthetic oils also have MUCH higher film-strength that conventional oils (say
10x), and don't need as much additive package as a result. Early synthetic
gear and transmission oils were just repackaged synthetic engine oil - and
they were good!
Synthetics are great for wide temperature ranges. Even the 20W50s stay very
pumpable in winter temperatures. The new 0W30 and common 5W30 synthetics
really do cut engine wear that occurs when cold engines start. If you drive
where you have to start cold and accelerate hard to highway speeds (like my
office - right on the freeway on-ramp at rush hour), these would be a good
idea.
Synthetics do not wear out; Ford labs have run them over 100,000 miles in test
engines - and then an individual engineer used the same oil in his own car for
years (Popular Mechanics article mid-70s). However synthetics DO still get
dirty, contaminated, and lose their additives with use. Amsoil was one of the
first to push extending drain intervals. There are lots of cases of long
distance truckers running the same oil for 100,000 to 300,000 miles - even
putting the old oil into a replacement engine. However to do so the regular
filter is still changed at normal intervals, and a bypass ultra-fine filter is
also used; and oil samples are sent in yearly for analysis. (I guess if
they're not selling you as much oil they want to sell you an analysis.)
Usually the oil that is added as it is consumed and as filters are replaced
will renew the additives in this kind of use. Amsoil sells bypass filter kits
and oil analysis kits too.
I think Amsoil is about as good as it gets - but I haven't used it for years.
I've been using Mobile 1 and Valvoline in different vehicles due to much lower
cost and because I still prefer to change oil about 7500 miles (filter at
3000). Having just torn down a 2.1 with over 100,000 on Mobile 1 and then
Valvoline it is very clean and shows negligible wear. (Heads were corroded -
should have used synthetic WATER.)
Also, after years of claiming Amsoil was better than any other oil, suddenly
they came out with the expensive new Series 2000 oils, and now talk about how
much better they are than other oils; and show test results that prove it. BUT
THEY NEVER SHOW TEST RESULTS COMPARING SERIES 2000 TO OLDER AMSOIL. I figure
either they want you to pay a lot more for very minor improvement, or maybe
the old oils suddenly don't compare as well??? Although they make good stuff,
Amsoil is really a MARKETING company - and I don't care for the way they
market.
Here in Texas I use 20W50 synthetics year round in waterboxers, and usually
10W40 in the "Audilet" VWs. They cost a bit more, but I like not changing oil
as often (with all our cars), and I keep cars a LONG time and a LOT of miles.
Tom
Austin
'87, '91, '97 Vans; 62 ragtop, '86 cab
----------
From: Vanagon mailing list on behalf of Chris & Aimee Uzzi
Sent: Thursday, October 09, 1997 8:35 AM
To: Vanagon@GERRY.SDSC.EDU
Subject: Re: Synthetic Oil(s)
Why did you choose a 5-50? My local VW shop recommended either 5-30 or
10-30 (Mobil 1). My driving conditions are mostly highway. Weather temps
vary between low 40's up to high 90's depending on the season. My '90 Westy
has just under 7k miles.
Any recommendations?
TIA
Chris
