oil myths?!?
 

Hello all. Since I am buying a car this week, I was reading about black/dirty oil from the dipstick when checking the state of an engine. I stumbled upon a site sponsored by Texaco and Chevron so I take their article with a pinch of salt, because I suspect they won't be 100% objective/forthcoming because of their own interests in selling oil! I got this interesting tidbit from the following site: Oil Myths and Facts

So following this logic, black/dirty oil showing on the dipstick would be good news as it would be a sign that the oil is working/cleaning the dirt out of the engine. Somehow, I can't get my mind around that. Is that a fact? Is the dirty oil = bad belief really a myth?

Yep it's a myth. Combustion is a pretty dirty process with lots of byproducts, from carbon deposits to metal particles from the metal-on-metal friction of the pistons and cylinder liners. Aside from lubrication one job of the oil is indeed to suspend all of that crunk and move it away, and this is where your oil filter comes in to help. Inevitably doing all that also means your oil will naturally get darker over time, and one reason why your oil needs replacing is because it loses its ability to suspend this crud effectively.

You can try reading Chris Longhurst's Car Bibles website - it's been around a long time and I learned a lot of general and not-so-general information from his work. Here's his Engine Oil Bible:
Car Bibles : The Engine Oil Bible

Yes, its a myth. Oil, with its additives can suspend a heck of a lot of carbon and neutralize combustion products. Big rig diesel engines typically go 35,000 miles per oil change and diesels burn a lot dirtier than gasoline. My BMW used to turn Chevron Delo 400 black almost instantly, yet oil analysis reports from 7-9,000 mile drain intervals showed the oil was still good.

Myth: <10,000 miles between oil changes under normal driving conditions.

Truth: 10,000-12,000 has always been my standard interval, and I have a friend in Italy who regularly goes 25,000 km and has never had the first lick of trouble with his cars.

Big rig diesels running over the road don't go any 35,000 miles between oil changes! Unless that are running around empty! The normal interval for newer ones is 25,000 miles. And they hold a lot more oil in the crankcase than our little Fits do. Over 10 times as much, 40 to 56 quarts of oil in their oil pans!

Also on this topic, I use to change the oil on my old 2002 VW Jetta TDI diesel every 18,000 miles. VW called for 10,000 mile oil change intervals and also required their own VW spec synthetic oil. Mine had 209,000 miles on it when I passed it on to my son. Had a 108,000 miles on it when I brought it used. Good solid little car!

Oh, oil from a diesel engine is black almost immediately after a oil change. Diesels require a special motor oil that holds soot in suspension rather than allowing it to drop out.

Road trucks with a full bypass filter system can go over a million miles on the same oil. You are right about the 25000 miles but that is with linehaul and city so 35000 is possible in a road truck with some city. The 15 liter motors holds 11 gallons and if we added a bypass system it would use 2.5 gallons more. My 8.9 liter holds 35 quarts and is changed every 12,000 miles in all city use.

Oil type is Valvoline blue which is cummins spec and is a very good oil. Oil turns black due to detergents and most auto oils turn different shades of brown due to being non detergent oils. Frequent Questions

Oil changes in 2007 and newer engine is also more frequent due to EGR heating the oil. EGR Systems and Lubricating Oil in Diesel Engines Which I can tell you really cause alot of problems with overheating and oil consumption to name a few. The older equipment with the new oils and fuels caused a lot of turbo failures.

But most company owned rigs do not run bypass oil filters. They are all spec'ed OEM. And I stand on the oil being black oil being caused because of Soot being suspended in the oil. Been that way for years now. It is not so bad anymore with the ULSD because of less soot being created by the engines. And I have never heard of turbo failures in older equipment being caused by new oils and new ULSD fuel. You will find older equipment injector pump failures be being caused by the new ULSD. It causes the seals to dry out. If you go over to - Bob is the Oil Guy, you can read up on these problems with the injector pumps. But the newer oils are actually causing far less turbo failures, because the oil flow better and handle heat much better than the old oils.

By the way, I do know of one commercial over the road company rig that ran way, way, over a million miles on the same oil without a oil change. No bypass filters, just normal filters. They tore it down, measured everything and put it back together and put the old oil back in it, and then ran it for another million. It was a test of a un-branded synthetic oil. They only changed the filters and top off the oil with replacement oil when the filters were changed. It was then tore down again, all parts measured, and put back together and retired to life as a city truck in Buffalo, NY. Never overhauled and after all that mileage, everything measured to new spec's. Never found out the brand of oil. Wife's uncle what head mechanic for the trucking company, and if he knew the name of the oil, he took it to the grave with him. He told me he had no idea what it was or where it came from or who made it.

Interesting thread indeed... :popc: What I can't get my mind around is how car owners bought into the "3k mi" oil change intervals that were being pushed... by both dealers and drive-thru places. :rolleyes:

just follow the maintenance reminder, op. dont just listen to your dealer. they are there to make money off service and will tell you many different things.

I was doing it way back in 1964! And that was what the car companies required for years until recently. I discovered you could push oil further when Mobil came out with Mobil 1 back in the mid 1970s. It was amazing that they could drive a car for 100,000 miles without a oil change. It was a feature story in Popular Mechanics that Mobil did just that, a gas guzzling Cadillac no less. That was when I switched to synthetic and started pushing oil change intervals. Been doing it ever since.
Stop Changing Your Oil - Edmunds.com

Interesting read parmm. Quite affirming coz I never bought into the "3k mi" bandwagon. Just seemed such a waste then and still is now (my thoughts). Well until the Fit's MM, I've always felt comfortable with the 5k - 7k interval window as far as I can remember. Though I have to admit, it's still taking a while to have full confidence in the MM. I remember when they were called "idiot" lights and now they've evolved into "smart" lights.

Refreshing to know that there is now data to support my gut habits. :) Thanks for the link. I hope you made it through the storm ok.

ive gone past the mm to like -500 miles before changing the oil. no issue. :D

Yeah, the few oil changes I've done based on the MM @ 15%, I've averaged around 6k - 6.8k which is fine with me.

Oem oil filters have a bypass. Its not the same as the one I referenced earlier but it is a bypass filter. Oil turns black due to detergents. M1 0w30 turned black and I am sure 0w20 will too in my car. That is what the main difference is between 5w20 and 0w20. 1 has detergents and the other does not. M1 5w20 turned brown with a orange tint in my Fit.

I know the system that you're referring to that was supposed to go further without a oil change and we had them on our trucks. We would have to add oil to a reservoir that holds 5 gallons of oil. We would have to fill it up every week so every two weeks or so we had a oil change. It was to last 500,000 miles with oil filter changes every 125,000 but it did not work out that way.

I counted the filters on my truck and it surprised me. 1 for coolant,1 for oil, 2 for fuel, 1 for DEF, 1 for the particulate filter exhaust, 1 for the trans (have a auto), 1 for air filter and 1 for the air dryer.

I believe it was Mobil one your wife's uncle was using. Mobil and the oil system above were working together and that was the selling point. It might be the reason the system did not work in our trucks.

Here is info on soot. http://www.gofurtherwithfs.com/White...%20Engines.pdf

Pure speculation on your part. There were refiners producing and experimenting with synthetic oils at that time. In fact several in the local area. There was also one experimenting with graphite in motor oils locally. That did not go over well.
Hauled petroleum products (gasoline, diesel, liquid asphalt, bunker oil, Jet A, JP8, and motor oil) here in the NY, Pa, Oh, and Ontario for over 20 years. Never heard of your referenced additive. It isn't available around here. Worked for one of the oldest petroleum transportation outfits in the country and we never used any oil or fuel additives. Also owned my own for a while. But I do know all about soot and how it makes used, even freshly used, diesel motor oil turn black. The only reason there is API "C" (Commercial) service classification designation is to identify "oils formulated to provide a higher level of protection against soot-related viscosity increase and viscosity loss due to shear in diesel engines". If you use a API "S" service classification oil in a diesel, you will quickly kill it. Started running diesels way back when I got back from Vietnam in 1970.

I wouldn't call adding more oil an oil change. Because whatever sludge or goo or other contaminants the oil picked up would remain there if you're just replacing oil that burned off (if the oil disappeared because it leaked out that'd be a different story).

Mobil1 and Delvac1 is advertised as the million mile oil. No speculation here and it still had to be changed at 100,000 miles.

http://www.mobil.com/USA-English-LCW...r-brochure.pdf

http://www.mobil.com/USA-English-LCW...a-brochure.pdf



Its not a additive its a system called CENTINEL Advanced Engine Oil Management System. It adds oil and from the tank on the back of the cab and pulls oil out and throws it into a empty tank or in the fuel. It worked but needed the oil in the tank to be replaced weekly. We would have to drain some of the oil out of the sump because it would overfill. Its a good system when mechanics are not there to do oil changes and the driver could manage the oil without worry even with its downfalls. Together Delvac 1(Mobil) with the Centinel system 1 million miles is possible. Since oil is taken out and new oil added and you're changing the filters its changing the oil as you drive.

Parmm is talking about diesel trucks. The system I was talking about changes the oil as you drive. Sludge is formed by water and carbon with help from sulfur. Trucks has a different fuel and operates under different conditions and the bypass part of the oil filter in a trucks oil filter absorbs water and since trucks run hours at a time sludge is not a problem. Cars have the oil changed 5000,10000 miles with low sulfur fuels so sludge is not a problem either unless you get bad gasoline and drive short trips. Trucks also burn 1 gallon to go 5-6 miles compared to 1 gallon 25-40 or more.

Most oils is a group 2,3 oil which both are made of saturated hydrocarbons which means they resist sludge build up and any water will burn off.

I didn't mean sludge in the technical definition of a certain problem that happened with oil a few years ago, I just meant goo in general.

Included in that goo is anything that ends up in oil that comes out with the oil when you change it- water, soot, metal particles that didn't get trapped in the oil filter, etc.

thought you were referring to FS Suprex Gold ESP, which was what you linked to. I know about the Centinel system, which will work with any good "C" category motor oil.