Less oil consumption when near add line?

[ledslinger]

My 2000 Concorde 2.7 has 193K miles on it and burns 1/2 quart during my often done 500 mile trip when starting at the full line. I normally keep it at the full line since this motor has sludge tendencies and has pretty high oil temperatures. The last trip I started with the oil level 1/2 quart low, and at the end of the trip it was 3/4 quart low, so had only consumed 1/4 quart. So during the last two 500 mile trips, 1/2 quart consumed when starting at full, and 1/4 quart consumed when starting at 1/2 quart low.

What does this say about an engine that consumes less oil when nearer the add line? I doubt the crank is getting into the oil when its at the full line and slinging it more, so why would it consume less with a lower oil level?

I have run mostly LL-01 5W40 over the last 125K miles, but run LL-01 5W30 in the winters, which are spent in Madison, WI. I've mostly run Motul 8100 Excess, but have run some Fuchs Titan and Liqui Moly also. Current 5W30 fill is Mobil 1 EP, which is the first non LL-01 oil I've ran in over 100K miles.

Transmission is original and I did one filter change at 60K and have done 4 dipstick pump out changes since then with ATF+4. It functions perfect except a little flare if you do a rolling vs a complete stop.

 

[clinebarger]

I had a 1997 S-10 4.3L truck that would drink a quart of oil then not consume a drop if the level was left a quart low. If you topped it off....It would eat that quart in @ 1000 miles.

If I didn't witness it firsthand, Id have a hard time believing it!!

 

[Bill_W]

The cylinder gets lubed by splash. Most likely piston ring involved IMO. Maybe check compression of cylinders. I am no expert.

 

[paoester]

Might be good to choose Mobil1 0w40 or Castrol 0w40 in that. Great German engine specs and handles WI winters nicely. Walmart doesn't charge must for them either.

Extra sloshing around near the windage tray, getting close to the crankshaft does it.
This subject was in another recent thread, and there were a couple of notable responses:

Originally Posted by Or
I have a '91 Audi, have had it 20 years. The first 2 years of the production with the new V8 engine, the factory spec'd 10.5 quarts (that's a lot of oil for a 3.6L sump!) and the dipstick was calibrated for that. The oil would disappear and it was about 2 quarts to top it off from the bottom of the dipstick to the Full mark. Eventually, people realized if they stopped topping it off, it stopped consuming oil. The pan was over-full in reality and crankshaft windage was aerating oil and causing it to burn. Eventually they just changed the sump spec to 8.5 quarts, lengthened and changed the dipstick, and the problem went away.
Originally Posted by JamesBond
I had a 4 cyl dodge minivan that would burn oil from the top of the dipstick to halfway in a couple hundred miles and then it wouldn't burn a drop in the next few thousand miles. It took me a while to realize this as I would usually try to keep it full so I was always topping it off.
We can call it the "Nissan GTR Effect" since Nissan says: "Engine oil maintenance
. When the vehicle is delivered, the
engine oil level is 0.39 in (10 mm)
below the H mark on the engine oil
dipstick for optimum high performance driving. The engine oil can be
filled up to the H mark if not engaging
in performance driving."

 

[JHZR2]

Ive read this a lot of times on different engines. Seems like it's a thing, for whatever reason...

 

[Jethro_Bob]

Originally Posted by clinebarger
I had a 1997 S-10 4.3L truck that would drink a quart of oil then not consume a drop if the level was left a quart low. If you topped it off....It would eat that quart in @ 1000 miles.

If I didn't witness it firsthand, Id have a hard time believing it!!


I believe you, I had a 1999 2.5L Ranger that would eat a half quart within a week but I could go 4,000 miles before it reached the add line.

 

[ledslinger]

Originally Posted by Bill_W
The cylinder gets lubed by splash. Most likely piston ring involved IMO. Maybe check compression of cylinders. I am no expert.



Since I'm getting 29 MPG in what is called a full sized car under ideal conditions, I don't think a compression test is warranted. Ideal conditions are cool enough to not need to run the AC. Most of the driving is about 72-75 MPH.

 

[oldhp]

How much oil are you putting in it? Pennzoil selector says 1.24gal = 5qts. Allpar.com says 4qts plus filter = 4.5qts? Mobil says approximately 5 quarts, which would be close when you add the 4qts PLUS oil filter 1/2qt
Oil going level down fast and then tapering off, to me is the crankshaft whipping the oil up into the cylinders, burning the oil down your 1/2 qts.
IDK

Good Luck!!!

 

[dlundblad]

Her Volvo is the same way. I used to keep it at the full mark and it'd go through oil relatively fast.

I changed it in April and haven't topped it off since. Just now a tad below half.

 

[Railrust]

Originally Posted by JHZR2
Ive read this a lot of times on different engines. Seems like it's a thing, for whatever reason...


I've heard about this too...want to say it has to do with the PCV valve system - if the oil is a little lower, less oil gets drawn into the intake...something along those lines.

Not sure how I feel about the whole thing...was watching a video on the Chevy Silverado catch cans....guy was saying to under fill it a quart and less oil would coke on the valves.

 

[Lapham3]

I've had similar experiences with some engines over the years and generally go for a mid point on the dip stick with oil changes.

 

[LotI]

Have you given any thought that your dipstick may not be linear?

 

[benjayman227]

Originally Posted by LotI
Have you given any thought that your dipstick may not be linear?


It most certainly is not linear, but it's probably not non-linear enough to be able to observe visually without calibrating the dipstick a few oz at a time. There are also a host of other variables like level ground, hot/cold, drainback time, etc that will overwhelm the non-linearity if not controlled for.

When OP says "1/2 qt low" and "3/4 qt low" it's not clear whether that's the estimated oil level referenced from the FULL line, or the actual amount of make-up oil added. Common wisdom is 1qt between ADD and FULL but it could be anything.

Edit: re-reading the post cleared that up. Calibration comment stands.

 

[paoester]

Originally Posted by benjayman227
Have you given any thought that your dipstick may not be linear?
Hey! Let's leave medical diagnoses out of this..

Non-linear on some engines: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5233030/re-2013-equinox-2-4#Post5233030
is an example of very non-linear.

 

[loneryder]

I think it is the pcv system. I've seen it on several of my vehicles including my Harley 103. If I fill it to mid point on the dipstick they don't "use" oil. Most cars have a weak pcv system for the size engine.

 

[barryh]

Originally Posted by loneryder
I think it is the pcv system. I've seen it on several of my vehicles including my Harley 103. If I fill it to mid point on the dipstick they don't "use" oil. Most cars have a weak pcv system for the size engine.


Agree, the increased air space in the sump gives the engine breather an easier time so less oil is lost to the intake system. On old BMW motorcycles the same effect of reduced oil consumption can be seen. BMW even went so far as to issue a service bulletin with words to the effect that the oil level should not exceed half way between min and max on the dipstick.

These days I personally never run any vehicle at the max mark. No reason to unless you are running long OCI's.

 

[bbhero]

Originally Posted by Jethro_Bob
Originally Posted by clinebarger
I had a 1997 S-10 4.3L truck that would drink a quart of oil then not consume a drop if the level was left a quart low. If you topped it off....It would eat that quart in @ 1000 miles.

If I didn't witness it firsthand, Id have a hard time believing it!!


I believe you, I had a 1999 2.5L Ranger that would eat a half quart within a week but I could go 4,000 miles before it reached the add line.



I believe you both ^^^^

An interesting observation about the lady's Camry was that I let it go down to the low line on the stick after changing the oil in it... It had about 1400 miles on it when I finally added oil to it. .. Filled it with about 4/5 a qt of oil... And it stabilized for another 1300 miles.. Really surprised me. Strange, crazy car

Runs very good though.

 

[DGXR]

Originally Posted by LotI
Have you given any thought that your dipstick may not be linear?

This was my first thought. Then I realized that a non-linear reading on the dipstick (in this example) means the oil pan has more volume at the lower points on the dipstick, which does not make much sense but I guess it's possible.
I have always believed it is unnecessary to top up the crankcase until the oil level gets close to the ADD mark... unless your engine is known to burn lots of oil.
It is interesting that Nissan recommends lower engine oil levels during performance driving. That seems counter-intuitive, but what do I know. Must be something specific to the GT-R engine design.

 

[D1dad]

Maybe I should try that on my 09 Nissan 2.5 oil burner. It's used oil since new and I just keep topping it off being upset about it. Never brave enough to let it go to the add line, or see how long it takes to get there.

 

[loneryder]

Originally Posted by D1dad
Maybe I should try that on my 09 Nissan 2.5 oil burner. It's used oil since new and I just keep topping it off being upset about it. Never brave enough to let it go to the add line, or see how long it takes to get there.

Just fill it to mid point between the 2 marks.