another dumb ignorant question

[first5ny]

BMW manual has oil viscosity chart that shows 5W30 oil being used up to 60 degrees. Above that temp. it looks like a 40 wt oil is needed. Why are so many people running 30 wt. oils that live in areas that get above 60 degrees. Does it have anything to do with the use of synthetic oil?

Would I be better off using a 5W40 over a 5W30 oil in new york? I wish I knew more about oil.

 

[Quattro Pete]

What's good for your BMW may not necessarily be good or required for other cars. Different engines require different viscosity oil. No mystery there.

I'd go by what the manual recommends. You could probably run something like M1 0w-40 or 5w-40 all year long in NY.

 

[csandste]

The only thing dumb and ignorant about your question was putting "another dumb ignorant question" in the heading. Had you made reference to suggested oil weight changes in your subject heading you might have gotten more responses.

FWIW-- My Hyundai Elantra has a recommendation for no 5w30 above 60F? on the web (didn't check) but 95 in the manual. The dealer uses 5w30 in all cars all year long, so this discrepancy is a problem with a number of cars.

 

[1maniac]

Almsot all BMW manuals show various weights for different outside temp ranges. However, this applies to conventional oil only. Somewhere in the manual they include a reference to "BMW special oils" which means synthetic lubes (GENERALLY speaking).

BMW changed all that and I think in 2001 and on BMW now specs synthetic oil meeting BMW requirements.