Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83 SMI; site husky.uucp Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!qantel!lll-crg!gymble!umcp-cs!seismo!rochester!ritcv!husky!mls From: mls@husky.uucp (Mark Stevans) Newsgroups: net.auto.tech Subject: 10W-40 in disfavor Message-ID: <274@husky.uucp> Date: Sat, 16-Nov-85 14:13:29 EST Article-I.D.: husky.274 Posted: Sat Nov 16 14:13:29 1985 Date-Received: Thu, 21-Nov-85 05:13:29 EST Organization: Eastman Kodak Company, Rochester, NY Lines: 12 According to my 1984 Toyota owner's manual, 10W-40 should be used for ambient temperatures above 40 Farenheit. However, my Toyota dealer says that 10W-40 has fallen out of favor with manufacturers. It seems that various polymers are mixed into 10W oil to "stretch" it to a 10W-40 multigrade are not quite stable enough, and break down too quickly in high temperatures. 10W-30 is about at the safe "stretch" limit, and so it is recommended instead. This seems to make sense to me, but might not a less polymerized oil, such as 15W-40, be better than the lighter oil, at least in the summer? Mark Stevans ritcv!husky!mls