Synthetic or regular oil change?

Source? Not that I know the first thing about oil, but just curious.

I switched to buying my oil in bulk through Toyota dealership, 8~9 liters at a time. They say it's Toyota oil, it certainly looks identical to the oil in the bottles, and I take them at the word. The recycle stream is awash in empty oil bottles (if they don't just end up in a landfill).

 

It has been told to me by several people at Toyota Dealers, it's pretty well discussed on the web and the attached link is for a promotion by Toyota and Mobil 1/Toyota oil.

Redirect Notice

 

It shows a promotion to change your oil with either Toyota oil or Mobil 1. I don't see how that means the two are the same, or that there's an association, ie: the Toyota oil is Mobil 1 with different additives. It could be, but that promotion doesn't say it. A screen grab:

 

This is interesting!
Can you reference your source for these statements?

 

Read through the promotion. Look at where to send your information to for either Mobil 1 or Toyota oil purchase. Search on Priuschat for Mobil 1 vs. Toyota oil. It has been discussed as well.

 

No - It's all over the web on different car forms and on this form as well. I did the research into Mobil 1 and other oils. 0W-40 is recommended by most of the European car industry and is factory fill.

 

For 10k miles, the difference between a true synthetic oil and labeled synthetic in the US is likely to not make much difference.
As long as the oil meets the specification Toyota calls for, it doesn't much matter who makes it.

 

A topic for eternal dispute is whether a Group III base oil (very highly refined petroleum) with the legal right in the U.S. & Canada to be marketed as full synthetic does as good a job as a Group IV base oil (polyaphaolefin) or Group V base (other), both so-called true synthetics. Except at extreme low temperatures (use PAO) the actual performance in the engine will be very similar.

Here's the link about Toyota oil vs. Mobil 1: Genuine Toyota Motor Oil vs Mobil 1 | PriusChat
I do not know about the Toyota specs. About the Mobil 1 specs...
--Viscosity index, the relative change in viscosity from 40°C to 100°C, is important. The higher the better; the less the viscosity changes (the oil thins) from warm to hot.
--The viscosity range permitted in the SAE J300 spec at 100° for a 20 wt oil is 6.9 to 9.2 centistokes. The difference shown between Toyota & Mobil 1 is not significant.
--The High Temperature High Shear HTHS viscosity at 150° is important. Higher is better for less wear. Lower offers less drag. The SAE J300 spec minimum for a 20 wt. oil is 2.6 centipoise. For the difference between 2.6 and 2.7, I'd pick the higher one, but the difference is little.
--Who says that one has a better antiwear package than the other?
--There is nothing in the specs and no test done at 0°C.

I stick with my basic rule...any top brand oil of the required spec will do a fine job.

 

When I said specification before, I actually meant oil standard.
Motor oil - Wikipedia
API | Oil Categories

In addition to viscosity and other physical properties, these standards also address additives, and some have fuel economy tests.
The owner's manual will list acceptable standards. For older cars, the new standard is generally backwards compatiable.

 

GM makes it easy, just look for the logo and/or check the charts.
https://www.gmdexos.com/owner/brands/