I am constantly learning more about new cars. They change so quickly today.

Well , motor oil is evolving too. Some real light viscosity stuff compared to ten years ago.
5W20 has become somewhat common now , butttttt........Toyota has a new one.......


0W8
Yes , zero w eight

That is some light oil. Full synthetic. Hard to find it except at a Toyota dealer. Quick search online I found a Toyota dealer selling it for $20 a quart.

Crazy stuff....

Cripes. 0W20 NAPA synthetic is $10/qt plus tax.

Engine aint gonna last long on that stuff.

Gonna have to go back to a horse.

My 0W20 is like water already

Ford went 5W20 over 24 years ago we are just getting old that it seems like yesterday.
my 2000 Expedition , 01 van , 04 f150 with 5.4 sons 11 5.0 f150 all running it

getting well over 200K on all of those 5.4s

GM went 5W30 a while ago also

idea I think is MORE FLOW less thick

Better gas mileage but biggest thing is cold/oil starved start-ups. Super light oil gets to where it needs to be very quickly. Modern cars have much closer/tighter tolerances , improved bearings , CADCAM designed engines and many other things that a thinner oil will protect at load.
Having a light oil for start-up is more important now.

Gone are the days when you could run a thicker oil for more protection under hard use. I used to run 20w50 Castrol in my cars that required 10w40.
Don't attempt to put a heavier oil in a modern car. You can quickly ruin the engine. Use what the manafactuer calls for your vehicle.

We'll back in my day... Oh, never mind.

How often do they recommend you change a 0W-8 oil?

Recommendations don't mean anything. Especially if you have a vvt engine or an engine like the gm's that are known for collapsing lifters. If the manual says 7,500, change it at 5,000. If the manual says 5,000, change it at 3,000.

This is still in it's Infantcy. Toyota only came with this oil about a year ago. They couldn't even get API certification until about 9 months ago. So all the cars that were delivered before that came with 0W-18 from the factory until they got certification which allowed dealerships to change the 0W-18 out and replace it with the 0W-8
Supposedly they were able to get the API certification because the oil is loaded with additives.

Change interval ? Whatever the manafactuer recommends. Sooner is good too , but that is a spendy DIY oil change at $100+ for oil and filter.

That sounds like go cart oil, I have trouble with my old dozer that old engine needs 15-40 low ash as it’s the only thing thick enough to keep the journals full of oil, as the CAT guy told me those engines were meant to run very low quality oils and today’s oils can be harmful to the engine as they flow too well.

Older Cat dozers used 30 wt, non detergent in the engine ,hydraulics and transmission.

The problem is finding 30wt that matches the old 30wt for viscosity most today is thinner and northland oil said that 15 40 low ash was as close as they could get, I run straight fifty in the transmission and final drives as mine is a manual with a cable run blade I use newer 15 40 on the clutch because I have it.

15w40 here

My 2021 GMC 1/2 ton 4wd, uses 0w20, but has 8 quarts in the pan.

I'm thinking when the warranty runs out of going to 5w20.

Yeah , more flow past the rings and seals.

the 0 represents start up viscosity

20 is operating temp viscosity

0 would technically get oil to parts faster and they would be the same at operating temp

Manufacturers have good incentive to build engines that last a long time. Vehicles/engines with a good reputation for reliability get sold more.

I can think of plenty of engines that have horrible reputations, and used 5w20 or 5w30.

Seems that engines are the last thing to crap out on a vehicle.
Most become a moneypit of parts and a rust bucket before the actual engine wears out.