why to change your oil

[thenubsterman]

Hey everyone this is a question i have to give a presentation on. Why do you need to change your oil, this doesn't only mean for psd. This could be for a lil crappy honda to. I figured i would come here cause you guys are always helpful. Please just let me have your opinion

[Big "O"]

Hi I saw your question and figured I would give you a few examples. First your oil is constantly being sheared which breaks the oil down, every engine has a certain amount of blowby which polutes the oil making it very acidic. Everytime you shut your engine off bearing surfaces and in the case of the turbo diesel or any turbo vehicle the shaft is very hot, if you take an amount of oil and put it in a hot pan it will burn off, the residual oil left on these surfaces when the engine is shut off causes this to happen inside the engine which is a contributor to oil sludging, the detergents in the oil help to wash this away the next time the engine is run but it will only do it so many times before it is no longer an effective cleaner. Some of the additives that aid in load handling ability fall from suspension as the oil is loaded over time, this is evident in vehicles that run N2O because of the shock loads put on the oil. Companies such as Royal Purple will do an oil analysis for you for short money, I think RP is like $11, this will give you information such as those metal suspensions, percentages of fuel in the oil and acidity of the oil, you can use this information to determine time periods between oil changes or the effect a new tune is having for example running way to rich and washing down the cyliders causing wear and poluting the oil. This is a very broad topic and this is only a little snipit of some major topics, however was just surfing around and just joined the forum, saw nobody had responded yet and wanted to throw you something, let me know any questions and I'll do the best I can to respond when I have time,
"O"

[topdwg]

Wow, I'm just surprised someone would even ask this?

[Big "O"]

The fact oil "wears" out has been beaten into most peoples heads, why it wears out is not always well spoken of. Without some base research the average person or car guy very well may have no idea.
"O"

[thenubsterman]

topdwg, i know why you change your oil, but I want more ideas, maybe different way to present it. Your guys ideas may be the same as mine, but stated in a different way. And i'm sure there are things I wouldn't think of right now, that you guys would.

[thenubsterman]

thanks Big O by the way, alot of info I didn't even think about, Your very descriptive I like that, and i know its a broad subject, and i only have 5-10 minutes to give it.

[choctaw]

The oil itself does not wear out as a rule, it's the additives that breakdown.

As little as a 10* rise in tempature from the optimum temp. can cause a severe breakdown in the oil.

[Big "O"]

Two methods that look at the effects of shearing and breakdown of the base oil are ASTM test methods D445 and D5275, as stated one of the major differences between oil other than the base oil which is a major seperator between syn and conv is the additives put in. Looking at these additives for wear such as zinc phosporus, anti foaming additives, detergents and ect would be a good way to present the breakdown of oil and the need to change it. Also if you buy an oil such as Royal Purple which the XLR can cost $10 a quart an oil change is $150 plus filter, spending $10 on an oil analysis could save you some money if the oil is still in acceptable condition.
"O"