Why/ why not run oil level at MIN?

[SHOZ]

Some of the Hyundai engines that destroy themselves, Hyundai issued a new dipstick that has full a half quart higher than the old dipstick.

 

[ATex7239]

Why not buy the additional quart and just save the remainder for a future change? Is one quart of oil changing your life?

Ex: 3.5 qts sump - buy 4 qts for the first change then buy 3 qts the second change.

That is what I used to do on my old D15 Hondas.

 

[javacontour]

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.

Seems like this is a solution looking for a problem.

If your vehicle doesn't warm up in a timely fashion, the problem is unlikely to be oil.

Seems like one is trading a few minutes of lower oil temps for far longer times of a lower volume of oil being expected to perform the task of motor oil.

If it were my car, I'd start an OCI will a full crankcase. I'd decide to add more should it need it depending on where I am in the OCI and the temps and expected use of the vehicle.

July or August in North America, half way through my OCI and it's a half quart low, I'm adding that half quart.

Winter and I'm 80% through the OCI and am 1/2 quart low, I'm probably going to let it ride for the next 1200-1500 miles.

Even that is subject to what I'm doing. If I'm going to drive from STL to Omaha, NE, I might top it off as the car is going to be on the road for 6-7 hours.

However, I still think, for most cases, starting a 1/2 quart low is a solution looking for a problem. At least for the cars I own.

I do see others who see high usage of the first 1/2 quart and then it slows.

I've had cars go the other way, they wouldn't use, wouldn't use, and then use a quart. My driving is largely interstate, so it's not water or fuel buildup that got burned off. It was how that car was on oil.

 

[SHOZ]

The manufacture has determine anything between low and full is OK right?

 

[eljefino]

The Ford 2.5 V6 from the Contour/ Mystique used to starve for oil in the corners, and the fix was to overfill it half a quart. This thread is nice for its anecdata of engines that like it one way or the other.

We had a guy on here a few months ago, he runs a fleet of trucks, and wanted to run them all on the "Min" line as well, just to be cheap. I advised against it as it would be poor morale for his professional drivers.

My dodge plow truck (318) is at the Min line right now with a frankenbrew. I start it up, plow two driveways, and park it. 15-20 minutes at a time- some work, some idling. Lots of hitting things and sloshing it around, too. I do it to get the oil up to temp faster, as OP suggests. Never seen an oil light.

Also remember the "Min" line is a historical artifact from when oil came in quart cans and you'd have to open one then finish it off. It's up to you to decide if the engine designers made the Min line the "real" minimum with the extra quart being extra, or if anything less than Max is unsat.

 

[dumkid]

I'd say that the real minimum is when there's no oil on the dipstick. I put oil in my engine when it's halfway between max and minimum

 

[MrGraybeard]

We owned a 2001 Prius, a car known for depositing oil mist in the intake manifold. Eventually the deposit interfered with the stop/start for the engine, which would throw a fault code and kick the car into limp mode, showing the infamous "red triangle of death." We currently have an '07 Prius that I've always kept half a quart below the full mark. At 160k miles it uses no oil between changes.

Earlier, I owned a couple of Mercedes turbodiesels that burned off the top half liter in the crankcase if you filled the sump to the full mark. Half a quart down, the engines stopped consuming oil.

 

[Titan]

For those commenting about experience with oil consumption at higher levels, that does match with some anecdotal evidence in a few engines that I've had where the oil level would drop to about 1/2 and remain there. Fill it up...and it would drop to the half-way mark again relatively soon and hold there again. It's certainly possible that the full mark is sometimes a bit "too full" regarding oil consumption. Then again, I have filled a 2018 Camry (with over 100,000 miles on it) 1/8" above full, and can run it 7500 miles without the level dropping a measurable amount.

 

[Davejam]

A larger volume of oil will heat up quicker, yes. But will risk overheating too.
The cooling system is designed with certain heat transfer(coolant, radiator condition, ambient temp), engine load, and volume in mind, if you are way off on one or more of those you could be in trouble.
In typical usage - highway driving it won't matter hardly at all - few degrees difference in operating temp if that.
But if you are driving hard in 90+F ambient, have any other issues with your cooling system, etc then it could matter a lot.

 

[GMBoy]

in some vehicles with weak or inadequate PVCs, it’s a good idea to keep your oil fill between the full and low mark. Not the low mark. I fill my Harley 103 engine about a half qt low and get less oil in the throttle intake.

That is absolutely true - I run exactly midway between low and full on my ultra classic (96ci) because anymore and my leg gets oil on it! No my Softail Deuce (88ci) I can run at the full mark and no issues due to the different oiling system.

 

[ecotourist]

For us old timer gas jockeys, we checked a lot of oil at those full service pumps, you never added oil until a car was a quart low, if only because it was adding a quart of oil or nothing.

Now in general, modern cars don't use nearly as much oil. Oil and transmission fluid are, again in general, the only two systems that have a low and full line. It's perfectly safe anywhere on or in between the two. I think this is a great discussion and falls between the two faithful BITOG responses.

The engineers know what they are doing.
It's cheap insurance.

I'm one of those old timers. I consider the top (full) and bottom (add) marks on the dipstick the recommended range.

My long dead '65 Comet 289 V8 used oil. I'd start off at the full mark and (while checking regularly) add a full quart when it got down to the add mark. That engine was dead by 80,000 miles but I don't think it had anything to do with whether or not I kept the oil level at the full mark.

My modern vehicles don't use oil (or a negligible amount of oil at worst). I start off at approximately the full mark and (checking occasionally) never add oil. There is no (or at worst a tiny) drop on the dip stick by the time a change is due. I never add oil.

I like the idea of having a big oil pan and therefore more oil in that oil pan. It's cheap insurance. But as a practical point I would only add oil if the oil on the dipstick ever got down to the add mark.

If your vehicle immediately loses the first half quart it's telling you something. In that circumstance I'd start off with an oil fill in the middle of the range. In my opinion, anywhere between add and full is within the recommended range.

 

[Luftmasse]

Heat up faster?

That's the thermostat's job.

 

[awguy]

On a 60's VW, if you ran a quart low you'd be at 1.5 quarts total. Ouch.

 

[javacontour]

On a 60's VW, if you ran a quart low you'd be at 1.5 quarts total. Ouch.

That's a good point. I've owned some Japanese vehicles with a 3L (give or take) sump. Being a quart low would be just under 1/3rd of the oil volume missing.

For an air cooled application, the oil is even more important when it comes to carrying heat, so being low on oil in that application wouldn't be a good thing in most cases.

I never owned an Air Cooled VW, could you run MORE or would bad things happen?

It sounds like you are saying the sump was 2.5 quarts. If so, what happened if you put 3 in and called it a day?

 

[awguy]

Yes sump is 2.5 quarts. Don't think I've ever over-filled but I do know the crank will hit the oil and aerate.

The oil bath air cleaner was just under half a quart so the last bits would get poured into the engine.

 

[Braapdaddy]

3/4 of the way up ......Incase the vehicle is growing oil its easy to see

I have cut a groove in my 6.4 power stroke at 3/4 for this reason

 

[javacontour]

Yes sump is 2.5 quarts. Don't think I've ever over-filled but I do know the crank will hit the oil and aerate.

The oil bath air cleaner was just under half a quart so the last bits would get poured into the engine.

I didn't think they had a very deep sump from the pictures I've viewed. I just didn't know how much margin there was for a bit of overfill. Apparently, not much.

Thanks

 

[twX]

Oil starvation is probably the most common cause of engine failure, and by running a lower oil level, you increase the risk. Some cars can have oil starvation issues in hard cornering even with the oil level in the normal range.

Even if an engine doesn't have a history of oil consumption, that can change quickly if a leak develops, so you want a bit of a safety margin.

Oil starvation can have catastrophic consequences, whereas the benefits of faster oil warm up are going to be very minor. How much warmer will the oil be during warm up? A few degrees? Faster oil warm up is beneficial to the condition of the oil, but this is more than outweighed by the fact that a smaller volume of oil will degrade and contaminate more quickly, unless the oil is changed more often.

 

[930.engineering]

It should heat up faster because there is a smaller mass of oil to be brought up to a certain temperature

For example your engine is 300 lbs + 20 lbs coolant/water. It's oil is about 4 qts/ 7 lbs.
What dominates the common heat capacity? Now you know what's you're missing.

by some fast calculations it takes 100+ watts of energy to bring 1L/qt. of oil from ambient to operating temperature.

Which 'some fast calculations'? Just guessing? Dreaming?

Will it overheat?

Nothing worth to talk about under normal circumstances.

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.

'Should'....
While a non issue there is some difference. More oil means more contact to the oil pan,
which commonly acts as a heatsink.

Thermal inertia is definitely lower.

'Definitely'. You should use 'definitely', 'calculation' (without evidence) and 'should'
a tad more carefully.

OCI will have to be shorter, but it would also be cheaper.

'Cheaper' is to save a running engine instead to experiment with its oil.

This seems like a really good idea for a short-triper.

It's 'really a bad idea' actually.

Am I missing something?

You recently joined a forum with thousands and thousands of contributions
and a decent search feature. Now you think you could reinvent the wheel . . . .

The engine is tip-top, but the car is totaled.

Conclusion? Now you suggest to ruin the engine? I'd suggest to avoid accidents instead.

I don't know.

Guess you got it.
.

 

[CKN]

You are not going to retire early running your oil at MIN. Any other reason (s) are pure speculation......