For 1 - I run Mobil 1 5W30 (previously recommend by myself)
For 2 - less viscosity = less protection & you yourself stated a 20 oil has less viscosity (I.E. thinner) than a 30 oil. Which is exactly the point of my post.
Your original post said a 5W20 oil and a 5W30 oil are indentical at operating temps. I.E. "the last number only deals with visocity at "LOWER" temperature - high REV's have nothing to do with it."
Which is incorrect! You even corrected yourself in your last post by stating the second number IS at higher temps (operating temp - 210d)
Also high rev's are where you encounter the worst thermal breakdown, cylinder pressures, plain old high speed moving parts (high revolutions!) and where an oil's viscosity is key to preventing damage and high wear!
So I definitely stand by my original post. What do you stand by?
Also; again... What oil filter do you use?
