Now, we’re approaching the ambiguity and conundrum on this oil issue that I find baffling. Hmmm

 

And let's not even get into the question of checking oil level hot vs cold which was never a thing in the past

 

Which raises an interesting question, Manual says wait 5-10 minutes, presumably for everything to flow back. Now—-does it skew the reading to wait longer, like overnight with totally cool oil?

 

You would think it would be the other way around after a change because in theory not every drop of the old oil gets drained. But I agree with you - with these engines that don't seem to consume, it should be fine as long as it's somewhere in the safe range. My wife's 2017 RX that had the 3.5 - never added a drop in nearly seven years (just traded that one) and same for my ES in more than five years.

 

Yes the manual does kind of "infer" it would skew the results since they want you to check it hot. If you wait overnight the oil allegedly "shrinks" in volume and gives a lower level compared with hot and is not the measurement condition specified by Lexus.

I keep meaning to quantify this effect and measure hot vs cold but I always forget

 

Did not realize this to now after reading my manual that oil capacity is for reference only and to measure hot. Goes against everything I have ever heard. If you fill to top mark hot after 5 min the next morning it will read above mark cold after all drained down.

 

I think we're all proving that as long as it's in range, don't obsess over it.

 

So if it’s 1/8 inch down when checked cold, it’s actually full as oil volume will expand when engine is warmed.
But waiting more than 5-10 minutes (a few hours) assures full return of oil from distant points of the engine, assuring more accurate and true reading.
I simply ask whether the manual wants you to wait at least 5-10 minutes (to enable most of the oil to flow back) or no longer than 5-10 minutes because they still want the oil to be relatively hot and expanded in volume when the dipstick is read?
Or are the differences in the readings, no matter how long you choose to wait, so minimal that doesn’t really matter so long as you’re between the two dots?
Finally and once again, I still don’t get how manual states it can be tolerated for the car to be driven when oil level could be as low as 1.5 quarts down and still reading between the two dots, and therefore not yet requiring any oil to be added. 🤔🫣

 

I suspect this is the answer without one ounce of mechanical training. Or are the differences in the readings, no matter how long you choose to wait, so minimal that doesn’t really matter so long as you’re between the two dots?

 

My 14.5 Camry was the first Toyota I’ve ever owned, and also the first car I’ve ever owned where adding the “capacity” oil amount didn’t bring the oil level to the top hole/ line. I thought they gave me the wrong dipstick. The level was only about 2/3 up from the bottom to top hole. And like you said, adding 5.7 quarts to our ES leaves the level about 1/4” from the top hole.

 

What makes sense to me is that you would check it hot but after sitting for about 10 min. Oil needs to be distributed through out the engine because that's how it runs under normal operating conditions... and whatever is left in the pan is whats important. ALL the oil will not be drained back into the pan after its ran to operating temps and then turned off and left sitting for 10 min.

You're sitting for 10 min to drain the oil back down the dip stick tube to be able to read it. Otherwise the dipstick will have oil halfway up it and make it un-readable.

I've never ever check oil in a cold engine. If I do its only for reference purposes to see how it relates to the actual level once its warmed up and checked the proper way.

 

Did a test today and looked at dip stick before driving and again after hot and waiting 5 minutes. Hybrid with 0w16 oil level was same on dip stick.

 

Lexus ESs are equipped with an engine oil level sensor so you have some backup that should give you some warning if the engine oil level gets too low.

I don't know how low the oil level has to get to trigger the warning; however, in all the Owner's Manuals in the "7-2. Steps to take in an emergency" subchapter, "Messages and warnings", there's this:
The manual doesn't specify what the specific combination of master warning light and warning buzzer occurs to indicate the severity of the detected low oil level condition.

The Lexus app's Vehicle Health Report Vehicle Status section also has a "Quantity of Engine Oil" entry indicating whether or not the "Quantity of engine oil is at the required level."
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Just checked mine first time in a bit. Spot on full mark.

 

All very informative. The only part I don’t get is that according to the manual no action need be taken even if the oil level is down over 1.50 quarts as that would be 1/4 distance up from add mark. I wouldn’t let mine go that low without topping off but the manual says oil level that low doesn’t REQUIRE adding. I find that amazing.