acceptable oil for 528?

[topgub]

I'm a Porsche guy, not familiar with BMW. My son's working on a 2000 528i sedan and wants to know which oils would be acceptable to use in this engine. The manual says "synthetic oil" but the car does have some leaks and as we all know, synthetic oils leak worse than regular oils.

[JhwShark]

I'm a Castrol 20/50 guy (no synth.) in all my cars. I used Penzoil in my first car, vw bug and blew the engine; castrol ever since. Though, I do not have anything newer than a '93. Synth is bad for some cars. I do not mind changing oil, or using the stuff that came from the ground.

Jon

[Manolito]

I used Castrol Syntec in my wife's '04 330 (70k miles) until the most recent oil change.

I switched to Mobile 1. About 1000 miles later she started complaining of a smell. Valve cover is leaking.

I will change back to Syntec, but I expect that I will have to change the valve cover gasket to get the leak to stop.

[topgub]

Thanx, I'll tell him to use the Syntec. What's with all of the thin viscosity oil? Is that because of cheaper steel cranks or for fuel economy? I use 20/50 Penn or Kendall in my 911's.

[Manolito]

I have heard the argument that lower viscosity oils should help with fuel economy, but my experience does not support that argument.

I think that the more important reason is that engines these days rely more on the oil to act as a cooling fluid.

[madjack181]

Castrol Syntec for sure.

[tmalaret]

Air cooled 911's are definitely Castrol 20/50 cars. My general experience has been that newer cars (2000 and later benefit from synthetic) and older cars (especially anything prior to the widespread use of synthetics) benefit from conventional. I would never use synthetic on cast iron. If you have a car with some oil leaks, that has been using conventional and you switch to synthetic it probably leak even worse. The synthetic is thinner.