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Posting-Version: version B 2.10 5/3/83; site tekchips.UUCP
Path: utzoo!linus!decvax!tektronix!tekchips!toma
From: toma@tekchips.UUCP
Newsgroups: net.auto
Subject: Re: Magic Oil Numbers
Message-ID: <262@tekchips.UUCP>
Date: Mon, 15-Aug-83 12:33:22 EDT
Article-I.D.: tekchips.262
Posted: Mon Aug 15 12:33:22 1983
Date-Received: Tue, 16-Aug-83 15:06:35 EDT
Organization: Tektronix, Beaverton OR
Lines: 19


	It used to be that single weight oils (such as 20W-20, 30, or 40) had
better high temperature performance (they would not decompose) than the multi-
viscosity oils (10W-30, 10W-40, 20W-50).  I don't know if that is still true.

	I've had 2 watercooled VW's and an Audi, and they all specify 20W-50
at temperatures above freezing.  In particular, they don't recommend 10W-40
above 60 degrees.  Here in Oregon, I have used Castrol GTX 20W-50 year around*
with no problems.  The Audi has 75,000 miles with no engine work (except for
warrantee valve seal replacement) and my old Rabbit had 65,000 miles with no
engine work when I sold it (it never used oil).  A few years ago the subject
came up here on oil grades for VW's and I was supprised to discover that 
everyone but me was using 10W-40.  One trouble with 20W-50 is that it is 
harder to find since most gas stations don't have it.  I buy it by the case on 
sale at a local auto supply store.

Tom Almy

* Oil and filter changed every 6,000 miles.  Cars are garaged.