20 vs 30 Watch out for AI slop here’s an example

[customboss]

 

[customboss]

5 hours ago, customboss said:

 

@Grumpy Bear watch and comment please. 
@OnTheReel

[customboss]

The linked video is Lake Speed Jr. (The Motor Oil Geek) debunking an AI video’s claim that 5W‑30 gives 40% better wear protection than 0W‑20, and his own data does not support that claim.[youtube]
Core points from the video
•    OEMs often spec thinner oils (like 0W‑20) in the U.S. than in other countries for the same engine primarily to meet CAFE fuel economy rules, not because thicker oils always protect better.[engineoilguide +1]
•    In over 10,000 used oil analyses from SPEEDiagnostix, 5W‑30 oils are roughly twice as likely to shear out of grade as 0W‑20 (about 40% vs 20%).[youtube]
•    When both oils stay in grade, 0W‑20 shows slightly better wear than 5W‑30, but the difference is so small it is not statistically significant.[youtube]
When wear actually increases
•    The big problem appears when 0W‑20 shears out of grade and gets too thin; wear then increases measurably.[youtube]
•    A 5W‑30 that shears out of grade does not show a dramatic change versus in‑grade performance, while a sheared 0W‑20 tends to drive wear up.[youtube]
•    Fuel dilution plus poor shear stability is the “double whammy” that pushes viscosity below what the engine was designed for.[bobistheoilguy +1]
Viscosity spread and shear stability
•    The wider the spread between the “W” number and the hot grade, the less shear stable the oil tends to be (e.g., 5W‑20 is more shear stable than 0W‑20; 5W‑30 more than 5W‑50; 10W‑30 more than 10W‑60).[bobistheoilguy +1]
•    This is because wider spreads typically rely on more viscosity index improvers, which can break down in service and drop viscosity.[engineoilguide +1]
What this means for 0W‑20 vs 5W‑30
•    0W‑20 can provide essentially equivalent protection to 5W‑30 as long as it stays in grade and is a stable formulation.[engineoilguide +1]
•    Higher viscosity oils sometimes reduce wear, sometimes do nothing, and in some cases can even increase wear depending on engine design, duty cycle, and oil chemistry.[engineoilguide +1]
•    The “5W‑30 gives 40% less wear than 0W‑20 in identical engines” claim is unsupported in the AI video: no actual data, mileages, oil brands, or specs were shown.[youtube +1]
Practical takeaway for you
•    Start with the OEM‑recommended viscosity, then confirm with used oil analysis; if wear metals are under about 5 ppm per 1,000 miles and the oil stays in grade, you are fine.[bobistheoilguy +1]
•    If your oil shears out of grade or wear is higher, consider changing brand or moving to a narrower‑spread grade (e.g., 5W‑20 instead of 0W‑20, or 5W‑30 instead of 0W‑40) if your operating conditions allow it.[bobistheoilguy +1]

[OnTheReel]

An 0w20 that doesn’t shear and a 5w30 that does are effectively the same thing at the end of the day. Difference is you are very hard pressed to find an 0w20 that stays in grade. We’ve all seen plenty of UOAs and you’re basically down to boutiques. And even then some engine platforms just dilute like crazy and trash the viscosity no matter what.
 

With that mind I think most average users who don’t sample and don’t care would be better served by even a cheap Walmart 5w30 than ANY 0w20. At least you get some margin. As someone who cares way too much, I’m not in that camp. But just speaking practically here. 

[customboss]

10 hours ago, OnTheReel said:

 

An 0w20 that doesn’t shear and a 5w30 that does are effectively the same thing at the end of the day.

 

Ding ding ding a winner! 8-9 cSt is the key. Our engines don’t care what the bottle says or a AI generated BS video that grumpy posted a month ago or so, that goober with glasses took apart. 
 

Did you pay attention to the video or my synopsis. MOST 0w-20’s stay in grade better than most 5w-30’s. 
 

CORRECT dilution is not shear. Some oil formulations chemistries resist fuel dilution better than others. Amsoil SS a bright shining star in that regard. 
Amsoil in all formulas deals with shear well too. 
 

Your observations are excellent just wanted to correct the shear issue among viscosity
 

 

Edited January 4 by customboss