Need for a thicker oil?

[Dominic]

What would indicate a need for a thicker oil - like a 10W40/15W40 instead of a 10W30. Would oil consumption be a good indicator of this? Mobil1 10W30 disappears too much for me to be happy, I pour in 5qts and I get 4qts out - Ive never had this issue with durablend Would switching to a 10W40 help this issue?

 

[sprintman]

Dominic Whats your primary concern when choosing an oil, fuel economy, anti-wear, or extended drain??. As US fuel pricing is so cheap that shouldn't really be of concern so go thicker. IMHO 5/10W40 or even 15W50. 20W50 is the best seller here but I don't like the idea of a 20W on cold starts.

 

[Dominic]

My main concern is antiwear above all - fuel economy would be nice but I would gladly sacrifice a mpg to gain 100,000miles of engine longevity. I am concerned with this engine oil consumption on Mobil1 though, my Firebird did it too (3800-II V6) when run on the stuff. Its really weird, I can only assume its due to the mobil1 thinning out over the 3,000 miles. I'm going to try a 10W30 this change, see if it goes away. If the 10W30 doesnt fix it, I'll try 10W40. I figure with my highload full throttle driving habits, I might be better running a 10W40 - we shall see. Thanks for the help, Australia sure throws new light on this subject 20W50, wow.

 

[BOBISTHEOILGUY]

Dominic, I myself use the schaeffers 15w40 here in jacksonville fl. I totally understand what your saying about heavier viscosity and wear protection. Balance is a very important part of wear protection. lets say you go with a heavy wt oil and on startup it doesn't flow all that well but maintains excellent hydrodynamic properties when hot. Problem, lack of lubrication is some of the critical areas on startup. On the other hand, you have too thin, pumps up fast but due to the heavier heat in this area and your heavy foot, you can shear out the hydrodynamic properties very easily, problem wear during operation. As Confucius says', there must be balance between your yin and yang my son, and as in life, so must oil have a balance of flow and wear protection and this is what barrier lubes are designed for, to act as the last line of defense in wear protection when flow is interrupted. If you get a chance, and ever make it this way, I'd like to show you first hand just how visc vs barrier lube effects wear protection.I'm not all that far from you and, if Tallahassee, about 100-150 miles tops. Give me a call sometime as you and anyone else that wants to is welcome to come by and see what I'm talking about. This has all my numbers so you can call if you ever decide to run over here. http://www.bobistheoilguy.com/orderpage.html [ July 30, 2002, 08:21 AM: Message edited by: BOBISTHEOILGUY ]

 

[sprintman]

Bob Could you give us a quick description of how viscosity and barrier balance affects wear? I can't visit just yet but will someday.