From: jim on 31 Mar 2010 10:47 jim beam wrote: > ooooh, "black oil" is evil!!! i didn't say that. Black oil is something perverts like you obsess about. > > dude, have you ever worked on diesels? those things have "black oil" > almost instantly. Dude, you are obsessed with black oil. > what then - change the oil every 500 miles? Yeah that was the question if some one chose to do that - what difference would that make to you? >or are > you going to bother to bust open a can of brains, figure out what > matters based on research and learn that "black oil" doesn't mean a > damned thing? It apparently means alot to you that simply mentioning it gets you so agitated. > > here's how it works: > combustion produces, among other things, soot. soot is black. i'm sure > you're with me so far. but, oil lubrication in a car engine uses > something called "hydrodynamic separation". simply, that means the > metal bits in a car don't actually touch, they are separated by an oil > film. that oil film has a measurable thickness So how does that explain your obsession? > > if your soot particles are small enough to "fit" in the hydrodynamic > film, the metals surfaces don't even know they're there. and that's the > job of the oil filter - to makes sure that the big particles are trapped > and only the harmless stuff flows through. The metal surfaces don't know anything and never will know anything, no matter what you hallucinate. > > beyond that, if the oil is chemically and thermally stable, and has the > chemical ingredients to handle other combustion products like acid, and > the filter is working properly, "black oil" is actually an indication > that the oil is doing its job properly - it is holding everything in > suspension and continuing to flow. So how does that explain your obsession with what other folks do?
From: Vic Smith on 31 Mar 2010 11:17 On Wed, 31 Mar 2010 09:47:17 -0500, jim <"sjedgingN0Sp"@m(a)mwt,net> wrote: > > >So how does that explain your obsession with what other folks do? Some people want to feel superior, or it could be they want reinforcement of their own beliefs, because they are not sure of those beliefs. But maybe when you see the same people saying they don't have to change their oil until 10000 miles go by, and they don't have to wax their car, it's a simple case of trying to justify their laziness and/or penuriousness. Like, "What, you bathe more than once a month? That's a crazy waste of precious water and heating fuel. Does no good and costs money." Could be something like that, but hard to tell without doing a psychological analysis. Personally, I don't care how often people bathe, so long as they don't stink up the place. Don't care at all how often they change their oil. --Vic.
From: SMS on 31 Mar 2010 11:34 On 31/03/10 6:12 AM, jim wrote: > The question is why are there so many zealots on the internet that feel > it is their mission in life to convince other motorists that it is good > to be driving around with black oil in their engines? I think the source of your confusion has been identified. You mistakenly believe that the color of the oil is indicative of its lubricity and its level of contaminants. Dark oil does not indicate the need for an oil change. The way modern detergent motor oil works is that minute particles of soot are suspended in the oil. These minute particles pose no danger to your engine, but they cause the oil to darken. A non-detergent oil would stay clearer than a detergent oil because all the soot would be left on the internal engine parts and would create sludge. If you never changed your oil, eventually the oil would no longer be able to suspend any more particles in the oil and sludge would form. Fortunately, by following the manufacturer's recommended oil change interval, you are changing your oil long before the oil has become saturated. Remember, a good oil should get dirty as it does it's work cleaning out the engine. The dispersant should stop all the gunk from depositing in the oil pan. The only real way to determine whether oil is truly in need of changing is to have an oil analysis performed. Since most people don't want to bother with this, it's acceptable to err heavily on the safe side and simply follow the manufacturer's recommended change interval for severe service. There is no benefit in changing the oil earlier than this. You're not increasing your engine's life by changing your oil every 2000 or 3000 miles versus 5000 miles.
From: jim on 31 Mar 2010 12:30 SMS wrote: > > On 31/03/10 6:12 AM, jim wrote: > > > The question is why are there so many zealots on the internet that feel > > it is their mission in life to convince other motorists that it is good > > to be driving around with black oil in their engines? > > I think the source of your confusion has been identified. You mistakenly > believe that the color of the oil is indicative of its lubricity and its > level of contaminants. No i don't believe anything of the sort. The color of the oil indicates the color of the oil. The question I ask is why do you care if someone else prefers not to have a certain color oil? > > Dark oil does not indicate the need for an oil change. The way modern > detergent motor oil works is that minute particles of soot are suspended > in the oil. These minute particles pose no danger to your engine, but > they cause the oil to darken. Actually that is not exactly true. There is a remote possibility that those particles could become harmful to the engine. For instance if you are tooling down the interstate and you head gasket lets loose and suddenly it dumps a bunch antifreeze into your oil. That will very quickly use up all the dispersant/detergent additives in the oil. That means the particles that were happily being held in suspension doing no harm will start to rather quickly precipitate and agglomerates into larger particles and that can cause harm. Fresh clean oil can absorb more antifreeze before engine damage occurrs than old black oil can. Saying extended oil changes are safe is based on the assumption that the engine is always going to be functioning properly. Keeping the oil cleaner than it needs to be can be insurance against certain types of malfunctions such as when excess fuel, antifreeze or dirt get dumped into the oil unexpectedly. Those may not be likely occurrences, but they do happen. Also, the older dirt laden oil is much less able to maintain it's viscosity and shear properties if the engine overheats excessively. And in this day and age excessively overheating engines is probably the number one cause of lubrication failures. Blow a radiator hose and the temps inside an engine can very quickly exceed 250C. > A non-detergent oil would stay clearer > than a detergent oil because all the soot would be left on the internal > engine parts and would create sludge. If you never changed your oil, > eventually the oil would no longer be able to suspend any more particles > in the oil and sludge would form. If someone changes their oil often enough so that it doesn't get black they never have to worry about whether they have reached the point where the additives can no longer protect the engine from the dirt. For instance if someone has a half a dozen cars, maybe its just a lot simpler and safer to change the oil when it starts to get very dark rather than keeping detailed records for so many vehicles. > Fortunately, by following the > manufacturer's recommended oil change interval, you are changing your > oil long before the oil has become saturated. Remember, a good oil > should get dirty as it does it's work cleaning out the engine. The > dispersant should stop all the gunk from depositing in the oil pan. > > The only real way to determine whether oil is truly in need of changing > is to have an oil analysis performed. But who cares if you happen to change the oil before you absolutely need to? I mean you probably don't wait to eat until you reach the point where it adversely affects health. You probably pea a lot more often than you really have to. Many people don't wait till April 15 to file their taxes. Doing things before it is absolutely positively necessary is pretty common human behavior. The question is why is this one particular behavior the one that gets so many people agitated? -jim >Since most people don't want to > bother with this, it's acceptable to err heavily on the safe side and > simply follow the manufacturer's recommended change interval for severe > service. There is no benefit in changing the oil earlier than this. > You're not increasing your engine's life by changing your oil every 2000 > or 3000 miles versus 5000 miles.
From: Jeff Strickland on 31 Mar 2010 12:41
"jim" <"sjedgingN0Sp"@m(a)mwt,net> wrote in message news:_6Odnew3LYMu5S7WnZ2dnUVZ_rKdnZ2d(a)bright.net... > > > SMS wrote: >> >> On 31/03/10 6:12 AM, jim wrote: >> >> > The question is why are there so many zealots on the internet >> > that feel >> > it is their mission in life to convince other motorists that it is good >> > to be driving around with black oil in their engines? >> >> I think the source of your confusion has been identified. You mistakenly >> believe that the color of the oil is indicative of its lubricity and its >> level of contaminants. > > No i don't believe anything of the sort. The color of the oil indicates > the color of the oil. The question I ask is why do you care if someone > else prefers not to have a certain color oil? > >> >> Dark oil does not indicate the need for an oil change. The way modern >> detergent motor oil works is that minute particles of soot are suspended >> in the oil. These minute particles pose no danger to your engine, but >> they cause the oil to darken. > > Actually that is not exactly true. There is a remote possibility that > those particles could become harmful to the engine. For instance if you > are tooling down the interstate and you head gasket lets loose and > suddenly it dumps a bunch antifreeze into your oil. That will very > quickly use up all the dispersant/detergent additives in the oil. That > means the particles that were happily being held in suspension doing no > harm will start to rather quickly precipitate and agglomerates into > larger particles and that can cause harm. Fresh clean oil can absorb > more antifreeze before engine damage occurrs than old black oil can. > Saying extended oil changes are safe is based on the assumption that > the engine is always going to be functioning properly. Keeping the oil > cleaner than it needs to be can be insurance against certain types of > malfunctions such as when excess fuel, antifreeze or dirt get dumped > into the oil unexpectedly. Those may not be likely occurrences, but they > do happen. Also, the older dirt laden oil is much less able to maintain > it's viscosity and shear properties if the engine overheats excessively. > And in this day and age excessively overheating engines is probably the > number one cause of lubrication failures. Blow a radiator hose and the > temps inside an engine can very quickly exceed 250C. > > > Sorry for jumping in in the middle here, but it appears to me that you're suggesting that the bad effects of a blown head gasket can be mitigated by clean oil. That's a huge falacy. If the head gasket lets go, it won't matter if the oil was changed 10 minutes or 10 months ago. The contamination of the coolant into the oil is the least of the problem when the head gasket goes. |