Why/ why not run oil level at MIN?

My Accent with the iron block 1.6L is a terribly cold blooded engine. OE it comes with a 180F tstat but it seldom would run that when really cold. And no real good heat unless above that. I put in a 192F tstat and that gives great heat but still it takes a long time to get to the opening temp of 188F.

With the manual transmission, any time you coast in gear or drive around town you will lose 10F, so I lug it when cold as someone else said and coast in neutral when coming to a stop. Only has 3.2 qt of oil to stat with.

When really cold into the single and negative digits I will completely cover the front of the radiator. Until it starts hitting 50F then it is half covered. The jiggle valve in the tstat I plug too. Found this makes a noticeable difference when warming up from cold.
My Hyundai is warm blooded. But not a mammal as it does not suckle its young.
 
It should heat up faster because there is a smaller mass of oil to be brought up to a certain temperature; by some fast calculations it takes 100+ watts of energy to bring 1L/qt. of oil from ambient to operating temperature.
Will it overheat? The oil cooling capacity should be the same because, the same amount of oil will flow and get in contact with the engine, there is just a smaller puddle in the oil pan. Thermal inertia is definitely lower.
OCI will have to be shorter, but it would also be cheaper.
This seems like a really good idea for a short-triper. Am I missing something?

In my case; my old Honda had a min-max of 2.5-3.5 and i've always just bought and poured in 3 bottles of whatever was on sale @ 6 month OCI (2-6k miles). The engine is tip-top, but the car is totaled :(. Now, my new Toyota has a min-max of 2.7-4.2 sooo I could do 3 bottles (which feels low) or I could do 4 bottles at ?... 6 month...1year... 6k miles... 10k miles... I don't know.
It helps to think in terms of percent.
If you have a 5 quart sump, and only fill it with 4 quarts, you are running with 20% less oil.
Parts of your engine may be getting less lubrication than they need. This could be harmful over the long term.

In my vehicles, I always make sure oil is exactly at the full mark 100% of the time.
 
The title question would be a perfectly reasonable question if slightly rephrased as "Why not run oil level near the MIN mark." That is unlikely to do any damage IF the user is careful not to let the level fall below that level and isn't taking turns near the limit.
 
1. Better cooling.
2. More oil means more cleaning, more volume to absorb deposits.
3. Less possibility to lose pressure in aggressive cornering.
Or to suck up into the valvetrain/cam phasers under high RPM. I have actually seen timing codes set with oil just at or below the minimum because the cam phasers wouldn't get enough oil at high RPM to retard the timing.
 
Or to suck up into the valvetrain/cam phasers under high RPM. I have actually seen timing codes set with oil just at or below the minimum because the cam phasers wouldn't get enough oil at high RPM to retard the timing.
Yep. It depends on the engine; some are more sensitive, and some are not. If warming up fast is imperative, good ole practice of running HVAC on cold first few minutes will do more than running sump on min.
 
Or to suck up into the valvetrain/cam phasers under high RPM. I have actually seen timing codes set with oil just at or below the minimum because the cam phasers wouldn't get enough oil at high RPM to retard the timing.

You would hope that the manufacturer who knows all the variables would have taken them into account when setting the minimum level.

It all boils down to if the minimum level mark has been safely determined. If it has then running at or above minimum should be perfectly safe.

What would be really useful is to have concrete evidence that particular manufacturers got the minimum level wrong. I know an example of where they got the maximum wrong but not the minimum.
 
I watched that video a few days ago and it was quite eye opening! I'm sure the average factory built engine won't see that kind of power loss, but it's still interesting nonetheless. For a car used only for drag racing it might be worth it to run the oil level lower in order to avoid that big power loss.
 
Ask GM. They say to run up to a quart over on LSX engines for track use because of how quickly the pump evacuates the pan at high RPM.
 
Ask GM. They say to run up to a quart over on LSX engines for track use because of how quickly the pump evacuates the pan at high RPM.

True, I remember when I first got my 98 Corvette, it's owner's manual said to run one quart over for track events, so in my mind I figured then it would be totally safe to run it like that all the time. So the entire 9 years I owned that car I ran it one quart over capacity, and I saw no issues from doing that (didn't seem to hurt the power level either, as it ran pretty quickly in the quarter mile, with it's best time being a 12.81 at 109.4 in the quarter mile)
 
True, I remember when I first got my 98 Corvette, it's owner's manual said to run one quart over for track events, so in my mind I figured then it would be totally safe to run it like that all the time. So the entire 9 years I owned that car I ran it one quart over capacity, and I saw no issues from doing that (didn't seem to hurt the power level either, as it ran pretty quickly in the quarter mile, with it's best time being a 12.81 at 109.4 in the quarter mile)
I ran mine right at the line or a half quart over even when ran as a daily just because I still tended to put my foot into it regularly.
 
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