Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 Fluke 8/7/84; site fluke.UUCP Path: utzoo!watmath!clyde!burl!hou3c!hocda!twitch!hocad!houxm!vax135!cornell!uw-beaver!ssc-vax!fluke!pwv From: pwv@fluke.UUCP (Pat Vilbrandt) Newsgroups: net.auto Subject: Re: Mobil One recommendations? Message-ID: <747@vax1.fluke.UUCP> Date: Wed, 3-Oct-84 14:24:54 EDT Article-I.D.: vax1.747 Posted: Wed Oct 3 14:24:54 1984 Date-Received: Sat, 6-Oct-84 05:34:50 EDT References: <166@maxvax.UUCP> Organization: John Fluke Mfg. Co., Everett, WA Lines: 74 [... slip-slide me some oil ...] -The Tin Man (Nipsy Russel) "THE WIZ" I, too, had many questions about synthetic oils and had heard many (unsubstantiated) horror stories about their use, so I decided to try my own (moderately) controlled experiment. I bought a shiny new Subaru 4WD wagon in Sept. of '77 and after the 1000 mi. check, ignoring the warranty warnings I put Mobil 1 synthetic oil in the crankcase. Thereafter, I changed the oil filter every 4-5K mi. and changed the oil every 25K mi. (I drive about 40 mi./day, mainly highway.) The oil consumption has been one quart every 1.5-2K mi. (mostly up the PCV hoses, I think). As for cost, at $3.95 (typ.) a quart, this schedule cost me about $0.0030/mi. Comparing this to using, say Penzoil 10W40 (my next choice after Mobil 1) at ~$1.10/qt on a 5K mi. change schedule, the cost would be about $0.0016/mi. So the lubricant cost works out to about double. The engine always performed well. The only external effect of using the synthetic was that the engine stayed relatively clean. What little synthetic oil leaked out of the engine didn't break down into sludge like petroleum based lubricants do. I theorized that this was true for the inside of the engine as well. After ~85K mi., as the result of engine block failure, I had the pleasant opportunity of tearing the engine down and rebuilding it. I was very pleasantly surprised at the overall condition of the engine, except of course for the problem that led me into the rebuild in the first place. There were almost no deposits or varnish at all in the engine. Most importantly, close inspection of the bearings, journals, wrist pins, rings, et. al. with micrometers and calipers showed almost no discernible wear (most within the normal to high side of the range for "new"). The only exception were the thrust surfaces on the center main which showed about 0.003" of combined wear, still well within the tolerance range (clearance limit 0.012"). For a 1600cc four banger driven relatively hard, I feel that the condition of the engine warranted the additional expense of Mobil 1. NOTE and WARNING to other Subaru owners of similar vintages: The engine block failure I speak of was caused by overheating (loss of coolant from water pump seal failure while highway driving). I didn't think the overheating was bad since I noticed the temp. gauge was high before I lost all coolant and stopped to add water which got me home. However, the engine block design (steel sleeves in an aluminum block) leaves the "bottoms" of the cylinders relatively unsupported. This overheating caused the bottoms of the cylinders to "sag" and stretch so that they were about 0.005" to large and up to 0.008" out of round. (I say "bottoms", however, Subaru engines are a horizontally opposed flat four, so it was really the "back" of the cylinder.) This resulted, of course, in compression loss and excessive oil burning at the bottom of the stroke. I do not, in any way, relate this problem to lubricant failure, since there was no cylinder scoring or wear. The relatively "thin" Mobil 1 (rated 5W30) appeared to have kept its film strength even when the engine overheated, for what it's worth. This is a distinct advantage of synthetics over regular petroleum based oils, I feel. So, after a 0.025" over rebore, new pistons and rings, the Sube is back on the road with Mobil 1 and 99+K mi., and probably will go another 99+K (I watch the coolant level religiously now). DISCLAIMER: My experience has been with MOBIL 1, a 100% synthetic oil. I have used no other materials or additives. I have had no experience with any other synthetics. I have no interest in Mobil Oil Co. or Subaru of America, financial or otherwise. This is only personal experience. I make no recommendations either pro or con for any of their products. Nyah, Nyah, Nyah.-- Pat Vilbrandt John Fluke Mfg. Co., Inc. Everett, Washington USA { uw-beaver, decvax!microsoft, ucbvax!lbl-csam, allegra, ssc-vax }!fluke!pwv