The notion that a car does not necessarily need 0W20 oil even if the manual calls for it stems from yje fact that some manufacturers specify heavier oil outside the US. That leads to the speculation that the lighter oil is being used here to get a higher EPA mpg rating.
I suppose that is possible but it is also possible that other places gave hotter climates and thus the heavier oil.
I don’t know the truth of it and I see no reason to use anything except called for in my owners manual.
The difference in price is very small between dino and synthetic. I have bought synthetic in the past for $13 with a $10 coupon, no coupons this year when I bought so I paid $19.95 for a 6 quart box of Havoline. Maybe I will try the other quart in my trimming mower.
I let my olm go over a few times on a 2007 MDX it was running perfectly fine with 220k.
The critical thing is making sure the oil level is okay.
Oil simply cannot maintain 100% film strength, anti-wear, etc. From thenfirstmcrank after a change, the oil begins to degrade. The better the oil, the longer the protective properties hold out. But by 5%, the oil is on it’s last legs and most assuredly is not offering the protection and lubrication it once did. That being said, the oil change indicator on most vehicles are a rough estimate of oil condition based on milage and load (best case), and many simplyncount miles…but it accounts for a little (very) margin.
Don’t run on oil until 0%.
My wife has a 2007 Lexus ES-350, and I own a 2014 Toyota Highlander. Both have the 3.5L V6. The Lexus recommended oil is 5W-30 (regular dino oil). Highlander is 0W-20 synthetic (only comes in synthetic).
Lexus NOW recommends 0W-20 for the 07 Lexus.
For over a year now I’ve been using 0W-30 in both vehicles. No issues what-so-ever.