Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site umcp-cs.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!umcp-cs!prophet From: prophet@umcp-cs.UUCP (Dennis Gibbs) Newsgroups: net.auto Subject: The letter "W" in viscosity specifications Message-ID: <176@umcp-cs.UUCP> Date: Sun, 30-Sep-84 10:04:55 EDT Article-I.D.: umcp-cs.176 Posted: Sun Sep 30 10:04:55 1984 Date-Received: Tue, 2-Oct-84 07:34:23 EDT Distribution: net Organization: U of Maryland, Computer Science Dept., College Park, MD Lines: 29 <> > Here's one for all you auto-netters that have been playing > with oily questions for the past few weeks: > > What does the 'W' stand for in 5W40, 10W30 etc.? (Maybe Weight?) > > George M. Verbosh The 'W' actually stands for 'winter'. It means what you can expect the oil's viscosity to be in winter conditions, specifically, at zero degrees F. If an oil has a rating of 5W40, then that means the oil should be the equivalent viscosity of a 5 weight oil at zero degrees F. There are also oils with a 10W rating, and a 20W rating. There is no such thing as 30W though, because most oils (with the exception of synthetics) of weight 30 have such high viscosity at 0 degrees F. that it is impossible to measure their viscosity. I almost forgot, there are also multiviscosity oils with a lower rating of 15W, but these are not very common, except maybe in the trucking industry. Dennis -- Call-Me: Dennis Gibbs, Univ. of Md. Comp. Sci. Center. UUCP: {seismo,allegra,brl-bmd}!umcp-cs!prophet CSNet: prophet@umcp-cs BITNET: GIBBS@UMDB ARPA: prophet@Maryland