Return-Path: Sender: (Marvin Kaye) To: lml Date: Tue, 03 Sep 2002 10:09:01 -0400 Message-ID: X-Original-Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 4.0b7) with ESMTP id 1720724 for lml@lancaironline.net; Tue, 03 Sep 2002 10:02:33 -0400 Received: from mta03ps.bigpond.com ([144.135.25.135]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Tue, 3 Sep 2002 09:54:42 -0400 Received: from hostname ([144.135.25.69]) by mta03ps.bigpond.com (Netscape Messaging Server 4.15 mta03ps May 23 2002 23:53:28) with SMTP id H1V8C600.0WN for ; Wed, 4 Sep 2002 00:02:30 +1000 Received: from wtpp-p-144-134-213-156.prem.tmns.net.au ([144.134.213.156]) by PSMAM01.mailsvc.email.bigpond.com(MailRouter V3.0n 65/15064034); 04 Sep 2002 00:02:30 X-Original-Message-ID: <00c101c25353$6c876a00$390736cb@direcpc.com> From: "Fred Moreno" X-Original-To: "Lancair list" Subject: Aviation vs. Automotive oil X-Original-Date: Tue, 3 Sep 2002 21:58:21 +0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 My recollection is that the key difference with aviation oils is the additive package. Auto oils are 15%+ additives, and because autos burn virtually no oil, the additives are formulated accordingly using the chemistry the manufacturer's judge to be best. In contrast, aviation engines burn lots of oil under much different conditions (high temperatures, continuous high power). Consequently the additive packages are very different. More importantly, the additives in aircraft oil are "ashless" meaning they will not burn and leave deposits in the combustion chamber that can cause mis-firing and detonation. So the word on automotive oils is, they are fine for automobiles, but could cause major detonation problems in your Lycoming or Continental because of the oil consumption in the big air cooled engines. Fred Moreno