prophet@umcp-cs.UUCP (Dennis Gibbs) (09/30/84)
<> > 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
ix1037@sdcc6.UUCP (Christopher Latham) (10/09/84)
Oils with a lower viscosity rating of 15 are usually also grade CD. In other words they are intended for use in certain diesels. For example my 83 Mitz. Turbo Diesel Truck uses CD oil with 15W-40 rating. Christopher Latham U.C.San Diego Dept. of Applied Mechanics and Engineering Sciences ..sdcsvax!sdcc6!ix1037