Recently, after changing my oil in my Ford Fusion a buddy of mine said my oil was low. I assured him it wasn't. The owners manual said 5.7 quarts (with the filter). I ended up putting in 6. After measuring several times in a few different days, it's just above the crosshatched section of the dipstick and a little below the top (max) hole.
My friend and I got into a spirited discussion on how much oil you should have in there. He claims it should always be right at the top Max hole and you if you aren't, are low on oil. I say as long as it is either in the crosshatched section or a little above you should be fine. I told him you never want to overfill or be at that over or into that top hole because then you are overfilling it (and that can be bad). He doesn't change his oil and has always gone to Jiffy Lube type places. His rationale is that they always show him his dipstick at the max level.
I am not messing around, so I came here to the oil experts. Who is right on this?
How full is full? Settle a debate
- Thread starter jcartwright99
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From an OCD point of view, I would guess to be FULL, the oil would need to be EXACTLY at the maximum line on the dipstick--IF that is what the manufacturer intended. With that said, within the crosshatches is operationally fine and I would not add until the oil hit the add line on the dipstick (but that is just me).
You are correct in this instance. Anywhere on the crosshatch is a safe operating level.
It's probably smart to keep the oil near the max line simply so you have extra capacity in case of a leak.
Also, don't exceed the max fill line. More is not better in that scenario.
Don't take our word for it, check your owners manual!
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Originally Posted By: jcartwright99
He doesn't change his oil and has always gone to Jiffy Lube type places.
I like to get it as close as I can to the top mark when changing but I don't add any throughout the interval unless it's at the bottom mark (I don't have to add any to any of my vehicles). I've overfilled enough times that I take it slow until I get it close to the top. Usually start with a quart less than total capacity and run the car a few minutes. Then add accordingly.
And don't take an internet forum's word for it. Read the owner's manual and see what it says.
Originally Posted By: JohnnyJohnson
Originally Posted By: jcartwright99
He doesn't change his oil and has always gone to Jiffy Lube type places.
1. Add the required quantity according to the manual.
2. Run the engine for a minute or so.
3. Check the dipstick. Use the level shown as a guide of where you should be level-wise.
Dipsticks are not always accurate, so if you put in 5.7 qts and it "appears" low, then you are in some respects, overfilling when you add enough to reach the max line. Having said that, if you added a small amount (0.1-0.25 qts), you likely aren't doing any harm.
My Cessna 177RG aircraft has a Lycoming engine. The sump holds 8 quarts. The filter and oil cooler hold exactly 1 additional quart.
When it's full, after a proper oil and filter change using 9 quarts, the dipstick reads 8 quarts.
Lycoming allows the engine to run, in flight, as low as 4 quarts. Testing shows that the engine will not suffer oil pressure problems in any aspect of flight until it's at 3 quarts on the dipstick.
There is nothing special about the engine. It has an oil pan and pickup much like a car.
For years, racers have improved power and economy by running the engine with less oil. As there is less oil to whip around inside the crankcase.
The bottom line is that every engine has a significant safety margin built in. At some point, under normal driving conditions, the oil pump pickup will be uncovered, say on a hill. Prob about 2 quarts total.
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Isn't this more of a philosophical debate? Is it a half quart above the low mark, or a half quart below the full mark?
I always keep it to the top of the fullest allowable mark that is not considered "Over Filled". This allows, in the case of a leak or if the engine decides to burn some oil, a safe reserve for me to notice it. If it's at the bottom of the "Safe" area and this happens you could be starving the engine for oil in some cases.
Also my OCD wouldn't let me do it any other way anyway. 
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Dyno guys will often drop a quart out of an engine to get a higher hp rating for their clients, it only helps a little like around 5hp.
Originally Posted By: Cujet
For years, racers have improved power and economy by running the engine with less oil. As there is less oil to whip around inside the crankcase.
I'm OCD about it.
I measure oil down to the ounce, I think my hyundai takes 5.23 quarts.
I try to get it as close to 5.25 as possible.
4WD
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You got him … how much did you win ?
I like it to land somewhere between the crosshatches and the hole on oil changes. If it ventures below the top of the crosshatch during the interval, I add.
Above the cross hatched area is overfilled....unless you know from experience that your dip stick is not 100% accurate and than your proper oil inventory places it slightly above the cross hatched region.
I never pondered about the holes in dipsticks. Fwiw, my 1999 Camaro oil dip stick has NO holes in it. So per your friend what do I do? Fill until it comes out the tube? Mine has the words "operating level" that points with an arrow to the very top of the X-hatch area. Without checking my other car, I don't think it has holes on the engine oil dip stick either. Maybe it's a Ford thing?
Originally Posted By: 69GTX
Above the cross hatched area is overfilled....unless you know from experience that your dip stick is not 100% accurate and than your proper oil inventory places it slightly above the cross hatched region.
I never pondered about the holes in dipsticks. Fwiw, my 1999 Camaro oil dip stick has NO holes in it. So per your friend what do I do? Fill until it comes out the tube? Mine has the words "operating level" that points with an arrow to the very top of the X-hatch area.
(J/K)My Subaru Outback manual says that the hole in the dipstick is the hot max level, and the top of the crosshatch is max cold, and operating anywhere in the crosshatch is acceptable.
I have had the experience that some engines will use oil above a certain level faster. So filling above that level just causes more consumption.
I am lucky enough to not own any vehicles at the present time that consume any measurable amount during an OCI.
So I fill to the top of the crosshatch cold, the morning after I change it, initially filling to that same level.
The only exception is my old BMW motorcycle with a sight glass. Filling only to the middle of the glass is my habit, since I know it will use any oil above that level quickly.
Originally Posted By: 4WD
You got him … how much did you win ?
Dealers on new cars overfill a little so lazy customers don't run low by the time the next OCI occurs.
In my case, out of warranty, I fill to the top mark and maybe a touch over, once it drops by
one notch or hole on the dipstick, then I top-up, usually takes 1/2 a quart to get back.
I never let it drop to the very bottom of the crosshatch! But I've seem others go that low and worse!
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