Originally Posted By: Ifixyawata
Originally Posted By: Rand
Is this hypothetical? most cars 20 years ago had a big chart of temps and recommended oils.
yes, THIS. Because I doubt any car, even 20 years ago required a heavy hitter like 20w-50. Was within range? Sure. Required that only? no. This sounds like a trolling post against thin oils.
Run 10w-30 and forget about it. Oh, you have winter? 5w-30. End of Story.
I'm tired of people demonizing xw-20 oils.
I don't demonize I just think that a 30 protects a bit better. My prior post was a joke about making a switch between extremes.
I know that my engine in my fusion was changed from 5w-30 to 5w-20 with no design or assembly changes.
I know that in the rest of the world 30 weight is specified by the oem.
I know that when I switched to 30 from Xw-20 oil consumption was reduced.
I know that 20 weights are recommended as a fuel saving measure to help oem meet CAFE requirements.
I don't have any data that tells me that 20 weight protects better. Actually there have been several posts quoting engineers telling people to run 30 weight if hard use is anticipated.
Do you have any evidence that a 20 weight is better for anything but fuel economy?
Also we are talking about a .6 HTHS difference. I'm running an HTHS of 3.5 and 20 weight starts at 2.9.
I don't think XW-20 is bad. I think xW-30 protects a BIT better. Not huge, not magical, but better. That's before factoring in fuel dilution.