OH OH, an Oil Topic

[BodybyFisher]

We have been saying this for years, to use the OIL LIFE MONITOR and that changing oil every 3K miles is overkill and wasteful but here it is in writing, Mike

PS, I don't know how accurate this article is, so don't shoot the messenger, I am just pointing out that 3K mile oil changes are a thing of the past as we have stressed.

The 3,000 Mile Oil Change Myth

By Bill Siuru, Greencar.com provided by:

According to a recent study by the California Integrated Waste Management Board, 73 percent of California drivers change their oil more frequently than required. This same scenario no doubt repeats itself across the country. Besides wasting money, this translates into unnecessary consumption of $100-a-barrel oil, much of it imported.

Using 2005 data, the Board estimates that Californians alone generate about 153.5 million gallons of waste oil annually, of which only about 60 percent is recycled. Used motor oil poses the greatest environmental risk of all automotive fluids because it is insoluble, persistent, and contains heavy metal and toxic chemicals. One gallon of used oil can foul the taste of one million gallons of water.

It’s been a misconception for years that engine oil should be changed every 3000 miles, even though most auto manufacturers now recommend oil changes at 5,000, 7,000, or even 10,000 mile intervals under normal driving conditions.

Greatly improved oils, including synthetic oils, coupled with better engines mean longer spans between oil changes without harming an engine. The 3000 mile interval is a carryover from days when engines used single-grade, non-detergent oils.

For several years, automakers like General Motors, BMW, and Mercedes-Benz have installed computerized systems that alert drivers via an instrument panel light when it’s time to change oil. As an example, the General Motor Oil Life System (GMOLS) analyzes the engine temperature, rpms, vehicle speeds, and other driving conditions to calculate the rate of engine oil degradation. Then, software calculates when the oil needs to be changed. Other systems work similarly.

Because of the many external conditions and parameters that have to be taken into account, calculating the precise maximum service interval using mathematical models alone is difficult. Now, Daimler AG has developed a more direct and precise way to monitor oil quality directly on board a vehicle.

Daimler uses a special sensor integrated into the oil circuit to monitor engine oil directly. Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change. Daimler uses the oil’s “permittivity,” that is, the ability to polarize in response to the electric field. If the engine oil is contaminated by water or soot particles, it polarizes to a greater extent and its permittivity increases.

To evaluate the quality of the oil, permittivity is measured by applying an AC potential between the interior and exterior pipes of an oil-filled sensor to determine how well the oil transmits the applied electric field.

Because not all impurities can be measured with sufficient precision via the electric field method, Daimler also measures the oil’s viscosity to detect any fuel that may have seeped into the oil. Daimler researchers measure viscosity while the vehicle is in motion by observing the oil's side-to-side motion in the oil sump. The slower the oil moves, the higher its viscosity. This movement is registered by a sensor and the viscosity is calculated on this basis.

A single sensor, along with the information already monitored by on-board computers, is sufficient to determine the various parameters of the engine oil. Daimler will likely use the technology first on its commercial vehicles. Here, large oil reservoirs mean larger quantities of oil can be saved. Plus, a predicted 25 percent increase between service intervals and reduced downtime will be of interest to fleets, and thus justify the added cost of installation.

[lothos]

I saw this article on yahoo this morning. I used to change my oil as soon after 3,000 miles as I could in my other cars. Sometimes that meant 3,000 and sometimes it was more like 4,000, in my Chevy Blazer and Olds Cutlass Supreme.

Becuase of posts on here I follow the oil life monitor. I start finding a time to change the oil when the OLM reaches 40% left and get it done before it hits 10%. I had my first couple oil changes in the STS done at a Goodyear place, but now I just do it myself. I've heard too many horror stories and oil is pretty easy. Checker Auto by my house takes used oil for free.

[JimD]

The article failed to point out that in some conditions (Fairbanks in January for example) 3,000 miles might be too long an interval. It all depends on how the engine is operated.

Down here south of I-20, my OLM runs down to 0% before I change oil/filter. In fact, I have run it to 0%, reset it to 100%, and run it down to 90% again once or twice because I was out of state and did not want to chance an oil change at some unknown wide spot in the road. Plenty of safety factor built in the OLM algorithm.

[BodybyFisher]

This is an example of the LIBERAL press minimizing GM's Oil Life Monitor (OLM) that has been used for quite a long time, a monitor that has shattered the 3,000 mile change interval habit. They could have TOUTED GM for their FORESIGHT and INGENUITY but they did NOT. As a matter of fact, they HARDLY talk about GM's OLM, probably because its an American development and you know because its American its no good.

But instead what did they do.... they TOUTED the Daimler method, that ISN'T EVEN BEING USED YET and THEN then soft soap its use on COMMERCIAL vehicles ONLY... The liberal America sucks mentality never ceases to amaze me. WE have better information HERE about the OIL LIFE MONITOR, they act like the OIL LIFE MONITOR is junk and went on to discuss a method that is NOT currently being used... They totally lost an opportunity to STRESS to GM owners the VALUE of the OLM.. UGH

Plus this statement is dead WRONG and simplifies the problem, its depletion of ZINC that creates the need for an oil change

"Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change" WRONG only part of the story and if the injectors don't leak not an issue.

This is what they said about the Daimler method:

A single sensor, along with the information already monitored by on-board computers, is sufficient to determine the various parameters of the engine oil. Daimler will likely use the technology first on its commercial vehicles. Here, large oil reservoirs mean larger quantities of oil can be saved. Plus, a predicted 25 percent increase between service intervals and reduced downtime will be of interest to fleets, and thus justify the added cost of installation

[BodybyFisher]

The article failed to point out that in some conditions (Fairbanks in January for example) 3,000 miles might be too long an interval. It all depends on how the engine is operated.

Down here south of I-20, my OLM runs down to 0% before I change oil/filter. In fact, I have run it to 0%, reset it to 100%, and run it down to 90% again once or twice because I was out of state and did not want to chance an oil change at some unknown wide spot in the road. Plenty of safety factor built in the OLM algorithm.

Keep in mind that the OLM was calibrated when the zinc levels in the oil were higher than they are now. Now that the zinc levels have been reduced, the OLM should be recalibrated but since that is not possible I think we need to be more cautious with the OLM. I realize that most of us put in a quart or two during the oil life due to consumption or leaking that would replenish zinc but still, I think we need to be more cautious now than were were before the zinc was reduced.

I have neglected to keep my word and send my oil to Blackstone. I wanted to change my oil, filter, record the mileage, reset the OLM then drive it till it gets to 50% and change my oil and send it to Blackstone, recording the mileage. By doing that, I could determine how much zinc was remaining. Confusing this would be the additional zinc gained by the need to add oil due to consumption (from all sources). But I was thinking of graphing three scenarios 1) those who added NO oil, 2) those who added 1 quart and 3) those who added 2 quarts). (those who add 3 quarts, have PLENTY of ZINC and need not worry, )

With this test it would be possible to determine the OLM's accuracy. Maybe if we found a trend we could say, OK, the OLM is off 10% because of the reduced zinc, so when it says 50% due to the reduced zinc its 40%. This reduction in zinc is more serious for pre-2000 Northstars.

What do you all think about us doing a test. I am sorry I dropped the ball on this when I last suggested this. I think I will put together a test procedure that whoever wants can do the test and record the results, if our database gets big enough we might uncover some interesting info. Not to mention, members MAY find that they have a leaky injector and THAT is the reason I was having driveablity problems. I will try to start a separate thread on this.

[Cadillac Jim]

Yeah, I was wondering why they didn't mention that GM (and possibly others) have been using OLMs for over 10 years. I suspect that they were in place when the Northstar system was introduced with the Avanti in early 1992. And, it's a feature of the OBD system, initiated by GM in the 1982 models, with vestiges of it back in the 1970's (remember shorting the "dealer service interface" jack pins and counting the flashes of the "Service Soon" light to get the codes?

GM has shown recent signs of waking up, though. They shelved capacity for huge SUVs when they closed four plants permanently, and acknowledged publicly that they didn't expect the higher fuel prices to be temporary. Chrysler was nearly put down for the count when they didn't acknowledge this after the 1972 oil embargo.

Now, where is the hybrid Aveo? Toyota has been selling the Prius since 2001, and Honda just introduced a hydrogen car. With a time-to-market of at least two years, GM should have been preparing candidates for introduction since 2005, but it looks more like 2007 was the start date for small, highly economical daily drivers.

Every time GM -- or anyone else -- is behind the curve when something disruptive happens, they give up market share permanently to whoever is ready with existing or new models when the public buys them. People who buy their first new car tend to develop brand loyalty to whatever marque they get. Thus really remarkable entry-level cars are what's required to get brand loyalty in the upcoming generation.

[Texas Jim]

Mike,

I have my kit from Blackstone.

Had the oil changed a couple of weeks ago and forgot to take it with me.

I will be taking a little trip in the next few weeks.

It will be time for another change when I get back.

I will REALLY TRY to remember to do it this time.

[steve6]

well.. I can't say i've ever really followed the 3000 mile interval, I've only changed the oil 3 times in my caddy in almost 2 years, lol, but I've only put 10,000 km's on it in this time, i changed it more because of the possible condensation factor more than anything.

But from a manufacturer standpoint why wouldn't they want this to happen? Oil will kill your engine if its not changed, and for the small cost of a oil change every three months the chances of a major engine failure will almost never happen. So over doing it is always better than under doing it. Look at all those toyota's that went to SLUDGE even at 3000 miles of oil in their engine.

[BodybyFisher]

well.. I can't say i've ever really followed the 3000 mile interval, I've only changed the oil 3 times in my caddy in almost 2 years, lol, but I've only put 10,000 km's on it in this time, i changed it more because of the possible condensation factor more than anything.

But from a manufacturer standpoint why wouldn't they want this to happen? Oil will kill your engine if its not changed, and for the small cost of a oil change every three months the chances of a major engine failure will almost never happen. So over doing it is always better than under doing it. Look at all those toyota's that went to SLUDGE even at 3000 miles of oil in their engine.

Read your manual, as a matter of fact read ANY manual from the sixty's it says change the oil every 3000 to 7000 depending upon the type of use, short trips change it more often LONG trips you can change it less often. WHO could keep track of that so we all changed our oil often as a result. The OLM takes the guessing out of the decision as it monitors oil temp, engine revolutions, run time, speed, rpm etc. It is a sophistocated device that monitors a lot of activity.

Obviously GM has confidence in the OLM to use it and recommend using it. When you make a statement like, "So over doing it is always better than under doing it", it means nothing at all. Yes, I guess I could WASH MY CAR everyday too, that is overdoing it also, is that better? How about putting PREMIUM in when the engine takes REGULAR, that is overdoing it that's better also? Hey, I can change my tranny fluid every 3000 miles also, thats good too huh?

Do a little research on the OLM before making unsupported, off the cuff statements and using a TOYOTA as support that does NOT have an OLM. I could give one SHI* less if the Toyota sludges up, they have a problem with the engine PERIOD. I dont know of ANYONE who has ever had ANY sludge in a NS, look into your CAM cover and see how clean your engine is. Its designed CORRECT.

I have posted EXTENSIVE information about the OLM OVER AND OVER from the guru, who was on the NS design team. Ill post it again later. The OLM works USE IT and stop wasting oil and money.

[jerrymac]

My first Caddy was a 1990 Eldo Barritz, and also the first vehicle that I owned with an oil life monitor.

It was driven both city and highway. I was surprised sometimes that I would get 6,500 miles on it before

it said 10%. I only changed the oil and filter when the OLM got down to 10%. Always used good quality

oil and OEM Delco filters and never had any major problems. When I traded it in it had over 200,000 miles

on it and still ran great. Wished all my vehicles had an OLM, then I wouldn't have to 'guess' when it's time

to change the oil.

I still only change oil in my 97 ETC when the OLM tells me to, although I do change the coolant every 2 years.

[catmendo]

hmm ... another oil discussion here ...

i once, thought it out as a counter, to an argument with my buddy Ed, when he told me

i should use syn. oil instead, of what i was using and if i remember right, i proved my

point, that if i used his kind of oil at X amount of price, maybe $5.00 a quart at the time ...

that i, could buy a new GM short block 350 vette motor, with my savings, for the course of

of my eng. life, as opposed to, if i used his wisdom/logic and oil ...

i like a good fight and i will study up later today the cost of changing the oil every 3,000 miles as opposed to changing it at say 10k ... with a filter change, every other time ...

gearheads, let's be think about particulates here and a filter only stops the big stuff and not the little stuff and

if some, of what i have read here is right, then a filter change every other time is no problem ...

some of the oil stuff, may be from the great guru himself ...

give me, some numbers here guys ??? the last time that i changed my oil i did it myself ...

what does a quart of the good stuff cost now ???

the last time i did it... 7 and a half quarts of rotella 15w/40W and a NAPA gold filter was about $30.00 ...

and, i would think that the price would be more now ..

just for ships and giggles, give me some numbers here to work with and i will try to crunch them ...

or not ... thanks ...

Lane aka/ Fred Gump ...

[catmendo]

"or not" oh boy, that statement worked out well, didn't it ...

................................................................................

please, do not respond to me, on my next to last post here ...

sorry guys , i am done and i am out of here ...

Lane

[BodybyFisher]

My first Caddy was a 1990 Eldo Barritz, and also the first vehicle that I owned with an oil life monitor.

It was driven both city and highway. I was surprised sometimes that I would get 6,500 miles on it before

it said 10%. I only changed the oil and filter when the OLM got down to 10%. Always used good quality

oil and OEM Delco filters and never had any major problems. When I traded it in it had over 200,000 miles

on it and still ran great. Wished all my vehicles had an OLM, then I wouldn't have to 'guess' when it's time

to change the oil.

I still only change oil in my 97 ETC when the OLM tells me to, although I do change the coolant every 2 years.

Sounds like you are maintaining your engine quite well.

[BodybyFisher]

For those of you who think that changing your oil every 3000 miles is the best course to take, consider that NO ONE not even the owners manual EVER said to do that. The need for an oil change is based not only upon the type of driving that you do, its based on zinc depletion. Short trips do not boil/burn out the impurities that get into the oil (moisture from condensation, fuel, etc). Short trips change it more often, long trips change it less often because with long trips the impurities are burned or boiled out. In addition, since the sixty's OIL has been much improved, carburators NO LONGER dump fuel into the combustion chamber, chokes are no longer used and EGR systems are refined. See the following written a LONG time ago by the guru, he was on the Northstar powertrain design team.

Please understand that this may be confusing as I have copied MANY of his OLM posts from different threads! He is THE MAN...Mike

***************************************************************************

One thing I can touch on and clear up.....the GM oil life monitor operation and my statement that ZDP (or ZDDP as you tend to call it here...most of the API literature just sticks to ZDP so I tend to use that) depletion is the basis for oil deterioration.

My spelling is poor but ZDP stands for zinc dialkyldithiophosphate which , as it sounds, is an anti-wear compound comprised of zinc and phosphorus.

ZDP is dispersed in the oil so as to be at a potential wear site if a surface asperity happens to break thru the oil film thickness causing the dreaded metal-to-metal contact. A molecule of ZDP must be present at that moment to prevent microwelding at the contact site which will cause material transfer, scuffing, scoring, wear and catostrophic failure. The concentration of ZDP in the oil will determine if there is ZDP present to work it's magic. The greater the concentration...the more likely a molecule of ZDP will be there...and vice versa.

By nature, ZDP is sacrifical. As ZDP is "used up" at a wear site to prevent micorwelding the concentration of ZDP decreases.... So...if you measure the ZDP concentration in engine oil in a running engine it will decrease at linear rate based on engine revolutions. Any given engine has a certain number of high potential wear areas where metal-to-metal contact could occur due to reduced film thickness and/or surface asperities....areas such as rubbing element cam followers, distributor gears, rocker arm pivots, push rod tips, etc...... The more of these areas the more ZDP depletion. The more often these features come in contact the greater the ZDP depletion. That is why, generally speaking, ZDP concentration in the oil, for any given engine, will decrease at a fairly linear rate when plotted versus cummulative engine revolutions. The more times it turns the more contact the more chance for wear the greater the depletion. This is as much of a fact as I could quote ever and is really not speculation or anything. It is proven beyond a shadow of a doubt in many studies. That is why it is ONE of the basis for determining oil life remaining and why it is THE basic premis of the GM oil life algorithm. It is only ONE of the things that determines oil life...but it is the one thing that can be tied to engine operation in a linear fashion and estimated very accurately by accumulating engine revolutions via a counter.

The GM engine oil life monitor counts engine revolutions and accumulates the number for the basis of the oil life calculation. It then adds deterioration factors for operating temperature, start up temperature, soak times, ambient, coolant temperature, etc... There are a LOT of factors that "adjust" or affect the slope of the deterioration but the fundamental deterioration is traced back to the ZDP depletion that is inescapable with engine revolutions. The specific rate of ZDP depletion is readily measurable for any given engine so that is the fundamental item that is first calibrated for the oil life algorithm to tailor it specifically to that engine.

You would obviously like to get the oil out of the engine before the ZDP concentration gets so low that it is ineffective at being at the right place at the right time and preventing engine wear so that becomes the long term limit on oil life for that application.

The other things that determine oil life such a acid build up, oxidation, petane insuluables such as silicon from dust/dirt, carbon or soot build up from the EGR in blowby, water contamination, fuel contamination, etc.... are all modeled by the multipliers or deterioration factors that "adjust" the immediate slope of the line defined by the engine revolution counter as those items can be modeled in other ways and accounted for in the immediate slope of the ZDP depletion line.

The algorithm was developed over the course of many years by several lubrication experts at GM Fuels and Lubes, spearheaded by Doctor Shirley Schwartz who holds the patents (with GM) for the algorithm and the oil life montitor. I had the luck of working directly with Dr. Schwartz when the idea of the oil life monitor first progressed from the theoretical/lab stage to real world testing/development/validation. There were fleets of cars operated under all conditions that deteriorate the oil life for any and every reason and , thru oil sampling and detailed analysis of the oil condition, the algorithm was developed, fine tuned and validated to be the most accurate way invented yet to recommend an oil change interval by. As just one example, I have seen cars driven side-by-side on trips, one towing a trailer and one not, for instance, to prove the effectiveness of the oil life monitor in deteriorating the oil at a faster rate just because of the higher load, higher average RPM, higher temps, etc...and it works flawlessly.

The oil life monitor is so effective because: it is customized for that specific vehicle/engine, it takes everything into account that deteriorates the oil, it is ALWAYS working so as to take into account THAT INDIVIDUALS driving schedule, and it tailors the oil change to that schedule and predicts, on an ongoing basis, the oil life remaining so that that specific individual can plan an oil change accordingly. No other system can do this that effectively.

One thing is that I know personally from years of testing and thousands of oil analysis that the oil life algorithm works. There is simply no argument to the contrary. If you don't believe me, fine, but, trust me, it works. It is accurate because it has been calibrated for each specific engine it is installed on and there is considerable testing and validation of the oil life monitor on that specific application. NOt something that oil companies or Amsoil do. They generalize....the oil life monitor is very specific for that application.

Oil condition sensors in some BMW and Mercedes products are useful, also. They have their limitations, though, as they can be blind to some contaminates and can, themselves, be contaminated by certain markers or constituents of certain engine oils. Oil condition sensors can only react to the specific oil at that moment and they add complexity, cost and another potential item to fail. One other beauty of the GM oil life monitor is that it is all software and does not add any mechanical complexity, mass, wiring or potential failure mechanism.

There is considerable safety factor in the GM oil life monitor. Typically, I would say, there is a 2:1 safety factor in the slope of the ZDP depletion curve....in other words, zero percent oil life per the ZDP depletion is not zero ZDP but twice the concentration of ZDP considered critical for THAT engine to operate under all conditions reliably with no wear. This is always a subject of discussion as to just how low do you want the ZDP to get before the oil is "worn out" if this is the deciding factor for oil life. We would tend to be on the conservative side. If the oil life is counting down on a slope that would recommend a 10K change interval then there is probably 20K oil life before the ZDP is catostrophically depleted....not that you would want to go there...but reason why many people are successful in running those change intervals.

Please...NOT ALL ENGINES ARE THE SAME. The example above is an excellent practical justification of why you would want to add EOS and change the 15W40 Delvac in the muscle car at 3000 miles max and yet can run the Northstar to 12500 easily on conventional oil. You must treat each engine and situation differently and what applies to one does not retroactively apply to others. This is where Amsoil falls short in my book by proposing long change intervals in most everything if you use their oil. It just doesn't work that way. You can run the Amsoil to 12500 with no concerns whatsoever in the late model Northstar because even the oil life monitor tells you that for conventional oil off the shelf. Would I do that to the 502 in my 66 Chevelle...NO WAY. Amsoil says I can though. Wrong.

There are entire SAE papers written on the GM oil life monitor and one could write a book on it so it is hard to touch on all aspects of it in a single post. Hopefully we hit the high spots. Realize that a GREAT deal of time, work and energy went into developing the oil life monitor and it has received acclaim from engineering organizations, petroleum organizations, environmental groups all across the board. It is not some widget invented in a week and tacked onto the car.

The oil life monitor is not under the control of a summer intern at GM Powertrain per an earlier post....LOL Not that a summer intern wasn't compiling calibrations or doing a project on it but is under control of the lube group with a variety of engineers directly responsible that have immediate responsibility for the different engine families and engine groups. The idea that a summer intern was responsible for or handling the oil life monitor is ludicrous.....LOL LOL LOL

[KHE]

This is an example of the LIBERAL press minimizing GM's Oil Life Monitor (OLM) that has been used for quite a long time, a monitor that has shattered the 3,000 mile change interval habit. They could have TOUTED GM for their FORESIGHT and INGENUITY but they did NOT. As a matter of fact, they HARDLY talk about GM's OLM, probably because its an American development and you know because its American its no good.

But instead what did they do.... they TOUTED the Daimler method, that ISN'T EVEN BEING USED YET and THEN then soft soap its use on COMMERCIAL vehicles ONLY... The liberal America sucks mentality never ceases to amaze me. WE have better information HERE about the OIL LIFE MONITOR, they act like the OIL LIFE MONITOR is junk and went on to discuss a method that is NOT currently being used... They totally lost an opportunity to STRESS to GM owners the VALUE of the OLM.. UGH

Plus this statement is dead WRONG and simplifies the problem, its depletion of ZINC that creates the need for an oil change

"Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change" WRONG only part of the story and if the injectors don't leak not an issue.

This is what they said about the Daimler method:

A single sensor, along with the information already monitored by on-board computers, is sufficient to determine the various parameters of the engine oil. Daimler will likely use the technology first on its commercial vehicles. Here, large oil reservoirs mean larger quantities of oil can be saved. Plus, a predicted 25 percent increase between service intervals and reduced downtime will be of interest to fleets, and thus justify the added cost of installation

The Chrysler method employs sensors to monitor the oil - just additional items to go bad over time vs. the GM system that is all software and is PROVEN.

The press hates GM - They never miss an opportunity to bash them. In the article above, they should have given GM the proper credit for being the first to develop the OLM. GM has a recall and it makes the front page, if Toyota or any other import has a recall, it is 7-8 pages deep in the paper if it even makes the paper.

Remember the fuel tank "issue" with the '73-'87 Chevy trucks? Dateline had to set explosive charges to make the truck catch fire in their demonstration of an impact.... GM should have sued the living &%^ out of Datline for that blunder...

[thu]

Remember the fuel tank "issue" with the '73-'87 Chevy trucks? Dateline had to set explosive charges to make the truck catch fire in their demonstration of an impact.... GM should have sued the living &%^ out of Datline for that blunder...

GM did sue NBC. They won big time.

[KHE]

Remember the fuel tank "issue" with the '73-'87 Chevy trucks? Dateline had to set explosive charges to make the truck catch fire in their demonstration of an impact.... GM should have sued the living &%^ out of Datline for that blunder...

GM did sue NBC. They won big time.

That would explain why the press hates them so much...

[Cadillac Jim]

They also found out that Ralph Nader had never had a driver's license when he published "Unsafe at Any Speed," and no one ever collected on a Corvair lawsuit.

GM isn't alone. Remember the Pinto gas tank? Ford was in court to address a court order to make a recall to change all Pinto gas tanks. They showed by facts and figures that more people would die driving the miles to and from their dealers to get the recall work done, due to normal traffic accident and death rates, than would be killed by the gas tanks if they just let the cars alone forever. The judge went ballistic, which is what you do when you have no rational answer to continue a dialogue. Remember the Chrysler Horizon/Omni? Consumer Reports, which had fallen under the control of Ralph Nader, rated these cars "Not Acceptable" because of their neutral, undamped steering at high speed. That's good if you have at least one hand (or knee) on the wheel but not so good if no one is at the helm; the logic from there was lost on Nader-led Consumer's Union.

What was Nader's position on the swing axles of the VW Bug and Mercedes Benz cars of the same era as the Corvair (early 1960's)? As far as I know he didn't have one -- but my sister and three of her kids were almost killed in a VW bug once because of oversteer in corrections after a pothole (her husband put a camber compensator on it before he would let her drive it again, and quickly traded it -- for a 1965 Corvair). I know of someone whose VW van rolled after driving under a bridge in a strong crosswind at top speed -- about 45 mph -- because of inherent instability of that vehicle and the transient in side forces as she drove under the bridge, then back out into the crosswind. The Mercedes vehicles of the time were known to have problems with sudden oversteer and spinout under pernicious conditions such as icy conditions or hard cornering on bad roads These peccadilloes of European swing axle vehicles were well-known at the time but never addressed by Nader.

[JohnnyG]

This is an example of the LIBERAL press minimizing GM's Oil Life Monitor (OLM) that has been used for quite a long time, a monitor that has shattered the 3,000 mile change interval habit. They could have TOUTED GM for their FORESIGHT and INGENUITY but they did NOT. As a matter of fact, they HARDLY talk about GM's OLM, probably because its an American development and you know because its American its no good.

But instead what did they do.... they TOUTED the Daimler method, that ISN'T EVEN BEING USED YET and THEN then soft soap its use on COMMERCIAL vehicles ONLY... The liberal America sucks mentality never ceases to amaze me. WE have better information HERE about the OIL LIFE MONITOR, they act like the OIL LIFE MONITOR is junk and went on to discuss a method that is NOT currently being used... They totally lost an opportunity to STRESS to GM owners the VALUE of the OLM.. UGH

Plus this statement is dead WRONG and simplifies the problem, its depletion of ZINC that creates the need for an oil change

"Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change" WRONG only part of the story and if the injectors don't leak not an issue.

I agree with this statement 100%. The Daimler method is garbage since we all know that the amount of solids in oil (meaning soot) is NO indication of the quality or longevity of the oil. Detergents are in the oil to do EXACTLY that, suspend the small particles of soot so they can be filtered out (if large enough) and pass through the filter if they are too small to cause any harm.

I can't believe that the 3000 mile oil change myth continues to this day! Of course the dealerships perpetuate this to their advantage. EVERY time I take my Dodge truck to the dealer for an oil change (they're still the only ones that will put 5W-20 into my Hemi) they totally disregard the manual's recommendation of 5000 miles and put a sticker on the windshield that calls for a 3000 MILE CHANGE!

Unfortunately the problem extends to GM dealers as well. After an instrument cluster change on my '99 Silverado, gues what feature/light was the only one left inoperable? You guessed it, the OLM!!! Complete with a brand new 3000 mile oil change sticker on the windshield!

[KHE]

This is an example of the LIBERAL press minimizing GM's Oil Life Monitor (OLM) that has been used for quite a long time, a monitor that has shattered the 3,000 mile change interval habit. They could have TOUTED GM for their FORESIGHT and INGENUITY but they did NOT. As a matter of fact, they HARDLY talk about GM's OLM, probably because its an American development and you know because its American its no good.

But instead what did they do.... they TOUTED the Daimler method, that ISN'T EVEN BEING USED YET and THEN then soft soap its use on COMMERCIAL vehicles ONLY... The liberal America sucks mentality never ceases to amaze me. WE have better information HERE about the OIL LIFE MONITOR, they act like the OIL LIFE MONITOR is junk and went on to discuss a method that is NOT currently being used... They totally lost an opportunity to STRESS to GM owners the VALUE of the OLM.. UGH

Plus this statement is dead WRONG and simplifies the problem, its depletion of ZINC that creates the need for an oil change

"Oil doesn’t wear out, but rather dirt and impurities cause oil to lose its ability to lubricate properly, dictating the need for a change" WRONG only part of the story and if the injectors don't leak not an issue.

I agree with this statement 100%. The Daimler method is garbage since we all know that the amount of solids in oil (meaning soot) is NO indication of the quality or longevity of the oil. Detergents are in the oil to do EXACTLY that, suspend the small particles of soot so they can be filtered out (if large enough) and pass through the filter if they are too small to cause any harm.

I can't believe that the 3000 mile oil change myth continues to this day! Of course the dealerships perpetuate this to their advantage. EVERY time I take my Dodge truck to the dealer for an oil change (they're still the only ones that will put 5W-20 into my Hemi) they totally disregard the manual's recommendation of 5000 miles and put a sticker on the windshield that calls for a 3000 MILE CHANGE!

Unfortunately the problem extends to GM dealers as well. After an instrument cluster change on my '99 Silverado, gues what feature/light was the only one left inoperable? You guessed it, the OLM!!! Complete with a brand new 3000 mile oil change sticker on the windshield!

The dealer disabled the OLM light??? I would have made them fix it and then report that to GM...

[Ranger]

Keep in mind that the OLM was calibrated when the zinc levels in the oil were higher than they are now. Now that the zinc levels have been reduced, the OLM should be recalibrated but since that is not possible I think we need to be more cautious with the OLM.

Keep this in mind Mike. It should negate any Lowered ZDDP fears.

There is considerable safety factor in the GM oil life monitor. Typically, I would say, there is a 2:1 safety factor in the slope of the ZDP depletion curve....in other words, zero percent oil life per the ZDP depletion is not zero ZDP but twice the concentration of ZDP considered critical for THAT engine to operate under all conditions reliably with no wear.

[BodybyFisher]

Keep in mind that the OLM was calibrated when the zinc levels in the oil were higher than they are now. Now that the zinc levels have been reduced, the OLM should be recalibrated but since that is not possible I think we need to be more cautious with the OLM.

Keep this in mind Mike. It should negate any Lowered ZDDP fears.

There is considerable safety factor in the GM oil life monitor. Typically, I would say, there is a 2:1 safety factor in the slope of the ZDP depletion curve....in other words, zero percent oil life per the ZDP depletion is not zero ZDP but twice the concentration of ZDP considered critical for THAT engine to operate under all conditions reliably with no wear.

That is good to know Ranger, Thanks

[MAC]

I strictly use the Oil Life Monitor. In fact, mine just expired so I'm changing my oil this weekend with full synthetic.

Ah...Oh....synthetic vs. dino.

[tjtjwdad]

I strictly use the Oil Life Monitor. In fact, mine just expired so I'm changing my oil this weekend with full synthetic.

Ah...Oh....synthetic vs. dino.

Well, its been almost 10 months and 10,000 miles and I'm down to 3% on the OLM and I've added a quart or two. Some tell me I should use synthetic but I usually stay with 5W-30, my car just turned 90,000, shes just getting broke in. I've thought about trying 15W-40 Rotella or Delo but I'm not so sure the Northstar needs that. My older cars (70 Pontiac and 92 Bronco definetly get it).

Jim

[Ranger]

No need for synthetic.