My wife just bought a 2025 Toyota Camry. All of them are hybrids now, but the ICE calls for 0W-8 oil. This is the same engine that in years past used 0W-20 and 0W-16. I've seen some forum posts and videos recommending the use of 0W-20 noting 0W-8 is too thin to offer the same level of protection. It's also believed Toyota made the change for gas mileage reasons only. Just wondering what the collective wisdom is out there?
If nothing else you need to use the manufacturer-specified oil to maintain your warranty.
Some test data here:
https://www.youtube.com/watch?v=sALAUhldASc
Mechanical engineers generally know what they're doing as far as lubricating engines. Pistons rings aren't nearly as stiff as they used to be. Piston rings scrape the walls of the cylinders, and the rings easily break down oil if you use too thin of an oil. When they're not stiff, like modern engines, you can use lighter oil. I have a piston from a 2010 Dodge Journey, and I can easily squeeze the piston rings with my hand. I also have a 1979 Pontiac that requires heavy oil (10W-30 or higher). Those piston rings are really stiff.
Engineers lessened the tension on the piston rings to get maximum fuel economy. Minimum tension =better fuel economy, but you get a lot more blow-by.
