Oil degradation

[Les]

Castrol ran a test that shows that oil degrades much faster when running it a quart low in the crankcase. I do not have any other information from the test other than the blurb below. Draw whatever conclusions from it that you want to. It is after midnight and I am at work and bored.

Les
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Top-Up Demonstration
We have run a program to compare the rate of oil degradation when the car is run at near
maximum versus near minimum dipstick oil level. It has shown conclusively that when run at the near minimum mark, the oil degrades at a significantly higher rate compared to the near maximum level. The measured degradation was most significant in respect of wear protection, HTHS viscosity (fuel economy impact) and low temperature, CCS, viscosity (start up).
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[Patman]

This is exactly why you should never let your oil level get to the "add one quart" mark, you should always be topping it off as soon as it's even the tiniest bit off the full mark. I like to add 100-200ml at a time as it needs it. It simply makes no sense whatsoever to wait until it's a full quart low in order to add oil. There is zero benefit in doing that, and like this article says, there is proof that this practice is harmful.

Keep your oil topped up folks!

 

[MGBV8]

Would adding an oil cooler improve on degradation position?

 

[Al]

quote:

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Originally posted by MGBV8:
Would adding an oil cooler improve on degradation position?

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Sure but is it worth the effort?? Don't forget there are other things that degrade oil-moisture, dirt, metal products, combustion products, depletion of additives, shearing. Heat is only part of the puzzle. Synthetics are also may better at resistign degredation through the heating process. For instance the 'Vette was able to dispense with an oil cooler by specifying a synthetic oil. For my money its not worth the effort.

And it its no great mystery why running a half a quart to one quart low would cause it to degrade sooner. If you have 25% less oil to work with the other oil will wear out proportionately sooner bc less oil is doing the work. A lot of what gets mentioned here and in articles is not rocket science

 

[greencrew]

So then this sounds like an oil quantity issue, making a larger oil pan or larger filter a good idea. I like the fact that the F-150 takes 6 quarts.

 

[Pablo]

Interesting indeed. I had not seen that before.

It totally fits and fills in a logic chunk in my oil thinking. Patman has it right. My cars barely consume oil, but I tell you I would never let one go below 1/2 mark. It scares the heck out of me when I pull someone's dipstick and the oil is just a mere tick on the tip, not even up the stick at all.

Greencrew - you about nailed it, the more volume the better (within reason of course). My Volvo 855 holds very nearly 7 qts.

I also think some cars when low on oil even have an oil scavenging problem on hard corners, leading to wear and oil degradation.

[ August 24, 2003, 10:19 AM: Message edited by: Pablo ]

 

[Patman]

quote:

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I also think some cars when low on oil even have an oil scavenging problem on hard corners, leading to wear and oil degradation.

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This is definitely true. Even though the LS1 Camaro/Firebirds hold 5.5 quarts of oil, and the LS1 Corvettes hold 6.5 quarts, these engines will starve for oil on hard corners, so hardcore autocrossers and road racers will add 1.0 to 1.5 more quarts of oil to them. GM even mentions it to Corvette owners to do this when racing (it's either in the Corvette owner's manual or there might be a video that comes with the car which mentions it, I know it's one of the two)

 

[MGBV8]

As there are other things that degrade oil-moisture, dirt, metal products, combustion products, depletion of additives, shearing, apart from heat, is it better to change oil on regular basis rather than extend oil change using expensive synthetics (in UK)?