[gravitylover]

This video does sort of explain why I get better mpg when the oil is over 5k miles and why it's getting better mpg now that it's over 100k miles. The oil is (even) thinner at that point and the engines tolerances have loosened up a bit. I do generally drive somewhat gently as far as rpm's are concerned with most shifts in the low 4k range other than the occasional hard pull on highway entrance ramps or when the road ahead of me dictates that a bit of fun is necessary but that's not often in the grand scheme of things. I didn't this summer but the last few I ran 5W30 and had no problems but my fuel economy was down as much as 2mpg per tank. I drive upwards of 30k per year so mpg's are pretty important to me, my fun is had more in corners than speed.

All that said, I like the way the engine responds to the Castrol Edge in the gold bottle. Not long ago a guy on here made a pretty strong point for the Idemitsu or Toyota 0W20 oil based on shear and viscosity characteristics so I'll probably use that in my next change at the end of this month.