Unless you're having issues with the current oil you're using, why switch? I doubt you'll be able to measure the improvement in overall economy.
You might query the Volvo dealer about this. I know Ford said a lighter weight oil was ok in a specific list of engines in the late 90's or early 2000's. Kenneth Waller http://www.tinyurl.com/272u2f ----- Original Message ----- From: "Joseph Tainter" <[EMAIL PROTECTED]> Subject: Follow-Up OT: Question for Pentax Auto Buffs Discussion Group > Thanks everyone for the replies to my question about 5W-30 oil. Now I > understand. > > A couple of you sent replies like this one from Paul: > > "At one time powerplant experts thought that wider bearing clearances > and heavier oil offered optimum protection. Eventually they discovered > that lighter oils and tighter clearances resulted in less wear, better > power and better fuel economy. What's more the 10W-40 oils sometimes > caused sticking of rings under some conditions. Not good." > > Does anyone know when this change in engine design took place? > > My 1989 Volvo 740 has 230,000 mi./370,000 km. and burns no oil. I have > been using Castrol synthetic 10W-40 oil in it year round. Should I > switch to 5W-30 or continue with the heavier oil? > > My wife was advised to use 20W-50 in her 1967 Austin-Healey Sprite. > Should she change to something lighter? > > Thanks again, > > Joe -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
