[Shop-talk] Oil, again

[Wayne]

On 11/2/2012 1:21 AM, Dave C wrote:
> However, apparently Subaru specs 0W-20
> full synthetic oil for the engine.  I was in the local chain auto parts
> store today picking up a couple of H4s and four five liter jugs of
> generic 10w30 that I use in just about everything and I saw that the
> ONLY 0w20 oil was Mobil 1 green cap, and it's REALLY spendy.

The ex-wife has a Scion TC with the same 2.2L 4 that Toyota puts in the 
Camary and probably other stuff. They spec'ed 0W20 for use in all 
climates except the hottest part of summer.  IIRC, I ran 0W20 in the 
winter & 5W30 in the summer. Castrol sells 0W20 in the regular GTX, and 
their synthetic blend.
I believe there are two reasons why manufacturers are going to super 
light oils: 1) they help make the EPA gas mileage numbers test better, 
possibly at the expense of higher engine wear.  2) Engines really are 
built to MUCH tighter tolerances & clearances then they used to be. 
Cylinder & bearing clearances of only a few the-thousandths are common.

-W