Suppose you run a car at normal OCI and other services specified at the dealership, however the car had its oil level kept at the maximum mark. And then car B which follows it everywhere, started in the same conditions everyday, and maintained identically, only car B had its oil maintained just above the minimum mark. I wonder at 200,000 miles, how much (if any) more wear car engine B would suffer rather that car engine A. A lot? A little? Barely perceivable?
Oil level variation
- Thread starter 79sunrunner
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I think there are too many variables to give a clear cut answer. Were any of the cars driven at high rpm on turns when the oil in the sump may cause the oil pump to go dry for a second etc?
lets jst say 50% highway 40% city obeying all traffic laws and 10% race track driven by the Stig.
None. Realistically speaking any oil over the minimum mark is simply filling empty space in the crankcase. In either scenario the oil pump will never be starved for oil so all bearing surfaces will get ample lubrication.
The only argument could be that car B has less oil to hold contaminants in, meaning the TBN would fall microscopically faster then car A. But even this, realistically, is hard to say if it will have any real effect on engine longevity.
Both oils will be equally contaminated with wear particulate, and both will be filtered the same by the oil filter. Car B should reach operating temperature slightly faster, which might actually afford faster lubrication and additive activation, but again, by such a tiny amount it would be nearly imperceivable.
The main issue is if car B starts burning oil and you forget to add some, well, that's the real-world issue...
The only argument could be that car B has less oil to hold contaminants in, meaning the TBN would fall microscopically faster then car A. But even this, realistically, is hard to say if it will have any real effect on engine longevity.
Both oils will be equally contaminated with wear particulate, and both will be filtered the same by the oil filter. Car B should reach operating temperature slightly faster, which might actually afford faster lubrication and additive activation, but again, by such a tiny amount it would be nearly imperceivable.
The main issue is if car B starts burning oil and you forget to add some, well, that's the real-world issue...
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^^^Good post.
In the old daze we used to run cars low on oil at the strip.
Deliberately.
At road courses I have seen cars routinely overfilled/underfilled depending on the owners whim.
One of my street toys has an accumulator from Moroso, if you ever checked that at the wrong time the entire stick can be covered!
In the old daze we used to run cars low on oil at the strip.
Deliberately.
At road courses I have seen cars routinely overfilled/underfilled depending on the owners whim.
One of my street toys has an accumulator from Moroso, if you ever checked that at the wrong time the entire stick can be covered!
Blackstone Labs says that the wear rate declines as oil is used, to a point, so the car with less oil may have less wear. All very academic. What are the chances that you car will fail due to oil related issues? 0.001%? Or are we talking about splitting hairs on oil consumption or compression at end of vehicle life?
I'd say that if the driving conditions and OCIs were such that the oil was never badly stressed then the answer would be absolutely no difference.
If however the oil *was* stressed a lot, and often run down to low TBN levels, then I believe that the one maintained near the top level could be in noticeably better condition.
I don't agree that the differences in TBN and contaminant levels would necessarily be "microscopic" either. My Prius has a 1.4L range (E to F) on the dipstick and only a 3.8L sump. I believe that the differences in TBN and contaminant levels could be up to 40% or more!
If however the oil *was* stressed a lot, and often run down to low TBN levels, then I believe that the one maintained near the top level could be in noticeably better condition.
I don't agree that the differences in TBN and contaminant levels would necessarily be "microscopic" either. My Prius has a 1.4L range (E to F) on the dipstick and only a 3.8L sump. I believe that the differences in TBN and contaminant levels could be up to 40% or more!
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Less oil will get to operating temps quicker, which is a good thing. The additives will probably get used up quicker, and hold less contaminants. Less oil will probably have less of a cooling ability in severely hot conditions, or while working the engine hard. I try and keep my oil level at the full mark.
Since oil cools as well lubricates the engine the oil could be hotter and provide less cooling. Thats one reason why NASCAR Sprint cars have a dry sump that holds gallons not 4 or 5 quarts.
In principle, I think a car should be capable of holding an indefinitely long circle, at maximum possible G force, engine speed held at redline, with the oil at the "add" mark. In reality, I don't trust a street engine is built to handle that without some degree of starvation.
Most people are unlikely to ever test that extreme of a scenario.
Most people are unlikely to ever test that extreme of a scenario.
My 1998 Corvette says it is okay to overfill the oil by one quart when doing track events, but that you should remove it afterwards.
During development of the C5, they had problems with oil starvation on skid pads, so they programed in an engine shutoff (slowly).
During development of the C5, they had problems with oil starvation on skid pads, so they programed in an engine shutoff (slowly).
On my cars with 4 1/2 quarts capacity is the add mark 1 full quart or 1/2 qt off of full?
When a dipstick shows "do not overfill" I would instruct a friend to maintain the level between full and add because I have seen a lady use the whole bottle when she was only a little low.
When a dipstick shows "do not overfill" I would instruct a friend to maintain the level between full and add because I have seen a lady use the whole bottle when she was only a little low.
Originally Posted By: 79sunrunner
Suppose you run a car at normal OCI and other services specified at the dealership, however the car had its oil level kept at the maximum mark. And then car B which follows it everywhere, started in the same conditions everyday, and maintained identically, only car B had its oil maintained just above the minimum mark. I wonder at 200,000 miles, how much (if any) more wear car engine B would suffer rather that car engine A. A lot? A little? Barely perceivable?
Normal street driving and assuming all factors equal, THIS ^^^^
Suppose you run a car at normal OCI and other services specified at the dealership, however the car had its oil level kept at the maximum mark. And then car B which follows it everywhere, started in the same conditions everyday, and maintained identically, only car B had its oil maintained just above the minimum mark. I wonder at 200,000 miles, how much (if any) more wear car engine B would suffer rather that car engine A. A lot? A little? Barely perceivable?
Normal street driving and assuming all factors equal, THIS ^^^^
Originally Posted By: 79sunrunner
Suppose you run a car at normal OCI and other services specified at the dealership, however the car had its oil level kept at the maximum mark. And then car B which follows it everywhere, started in the same conditions everyday, and maintained identically, only car B had its oil maintained just above the minimum mark. I wonder at 200,000 miles, how much (if any) more wear car engine B would suffer rather that car engine A. A lot? A little? Barely perceivable?
Answer: Car B would have 0.09735628% higher wear
Suppose you run a car at normal OCI and other services specified at the dealership, however the car had its oil level kept at the maximum mark. And then car B which follows it everywhere, started in the same conditions everyday, and maintained identically, only car B had its oil maintained just above the minimum mark. I wonder at 200,000 miles, how much (if any) more wear car engine B would suffer rather that car engine A. A lot? A little? Barely perceivable?
Answer: Car B would have 0.09735628% higher wear
Originally Posted By: Corvette Owner
My 1998 Corvette says it is okay to overfill the oil by one quart when doing track events, but that you should remove it afterwards.
If I had a Corvette...every day would be a track event...even my trip to Home Depot.
My 1998 Corvette says it is okay to overfill the oil by one quart when doing track events, but that you should remove it afterwards.
If I had a Corvette...every day would be a track event...even my trip to Home Depot.
Originally Posted By: FZ1
Better to keep the oil at the full mark. More oil volume to spread the heat/contaminates. Hard to believe some can overthink a simple Full mark on a dipstick.
+1
Better to keep the oil at the full mark. More oil volume to spread the heat/contaminates. Hard to believe some can overthink a simple Full mark on a dipstick.
+1
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I used to corespond with a Nissan Z engine builder called Zdoc,and he always recommended to put an even 5 quarts in a Z32`s 4.5 quart sump.
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