Oil return ports

You are really splitting hairs here.

Read what I said "The only reason Toyota declines to actually name other oil weights that you can use is because of U.S. federal laws."

That does not equal the EPA explicitly telling Toyota what they can use.

I never stated that there is a law which on its face says X manufacturer must use only Y oil. But that is how you are trying to construe what I've said.

If you can't differentiate the nuance between the two then I don't know what else to tell you.

 

Interesting that this article says 91 Octane. Curious.....

 

There are different methods for octane rating.
91 is Research

 

He’s talking about the federal regulations stated in the post he quoted. According to that post, there are some oil viscosity/weight combos that are not listed in the manual but suitable as far as physics is concerned. So, this isn’t a physics question.

 

And 91 Research octane is roughly equivalent to 87 (R+M)/2 octane which is what you will find posted on gas pumps across the U S of A.

 

That is my understanding.

• 87 AKI = 91 RON
• 91 AKI = 93 RON
• 93 AKI = 98 RON
• 100 AKI = 104 RON
• 104 AKI = 108 RON

 

How do you know that what Toyota calls “octane rating” is RON? Is that a guess?

 

Agreed, no evidence shown. EPA sets mileage goals :: industry response includes tighter tolerances and lower viscosity oils.

Extraordinary claims require extraordinary proof - on your part. Not a snipe hunt on our part. Show me.

 

That would've been a Ford.

That would be a bad idea even with amply sized oil passages. With heavier weight oil at operating temperature, the oil filter bypass valve will open more often, causing more unfiltered oil to pass through than with oil weights specified in the owner's manual.

 

No guessing, it's spelled out quite clearly in the manual.

 

I guess educated guessing?

 

The manual can be very educational sometimes.

 

Yep. RTFM...

 

Buy Rivian

 

Or sell the boat.

 

Keep both and get Gf... No?

 

It does exist.

 

every 5K miles or 6 months, whichever comes first

 

There is a wealth of info here, including links to TIS free manuals.
Thanks!

 

Oh gee another non-oil thread.