What mechanics won't tell you

[BodybyFisher]

But we have been saying for years, use the OIL LIFE MONITOR and nix the 3000 mile oil changes

http://finance.yahoo...mod=family-auto

You don't need to change your oil every 3,000 miles.

Here's a secret that mechanics don't want you to know: You really don't need to have your oil changed every 3,000 miles.

It's a waste of a precious resource -- not to mention money -- to take your car in every 3,000 miles or three months, experts say. On average, most cars don't need an oil change for 7,500 miles.

"The oil change itself is a loss leader," said Austin Davis, whose family has been in the car-maintenance business in Houston since 1937. "Most repair shops will lose money or at best break even on a $25 to $28 oil change," he said. "The whole idea is to get you to also buy an air filter, rotate your tires or buy something else while you're there."

Complaints about auto repairs consistently rank among the top 10 grievances filed to state attorneys general, according to the National Association of Attorneys General. In 2008, the latest figures available, auto repair complaints ranked No. 6 on the list.

Because car manufacturing has become so sophisticated and less reliant on human intervention -- more computers and technology are producing and installing parts, for example -- the car-repair business isn't as robust as it was 10 and even five years ago.

"The easiest way to make up for money that you're losing or to increase profits is to turn up the up-sell button on all your services," said Philip Reed, senior consumer-advice editor for Edmunds.com. "Mechanics want you to get brake jobs earlier than you need them or change oil filters more frequently."

Sometimes, however, we are our worst enemies when it comes to explaining what is wrong with the car and giving away too much information. "Never reveal your budget," said Mr. Davis. "If there's steam pouring out of the hood of your Mercedes, don't tell the guy 'I hope this isn't going to cost me $2,000.'

"He'll be thinking, 'How about $1,995,'" he said.

There are no hard-and-fast rules about maintaining cars because they're all different. But experts do agree on this rule of thumb: Use your car manual as your guide. It will tell you at what mileage mark the oil should be changed or the transmission fluids flushed and what intervals that maintenance should follow as well as a host of other upkeep tips.

"If there's a conflict between what the owner's manual recommends and what the dealer recommends, follow the owner's manual," said Reed. "The manufacturer made the car; they should know what it takes to maintain it and keep it running."

[Cadillac Jim]

My OLM is running about 50% right now. I'll take a look at the oil and if it looks good, I think I might let it run down to 40% before I buy eight quarts of Mobile 1.

[JimD]

But we have been saying for years, use the OIL LIFE MONITOR and nix the 3000 mile oil changes

http://finance.yahoo...mod=family-auto

You don't need to change your oil every 3,000 miles.

Here's a secret that mechanics don't want you to know: You really don't need to have your oil changed every 3,000 miles.

It's a waste of a precious resource -- not to mention money -- to take your car in every 3,000 miles or three months, experts say. On average, most cars don't need an oil change for 7,500 miles.

The folks who believe in 3,000 mile oil changes also believe you can't lose money in real estate. Urban mythology, or "my daddy said...."

The OLM algorithms were developed following thousands of laboratory hours testing oil at various miles of service. Most other car makers have a similar system but they cannot approach the accuracy of the (patented) GM system. We can only speculate why GM does not make the car buying public aware of the OLM as well all the other vehicle systems integration that has taken place since the 1980's and continues today.

[adallak]

But we have been saying for years, use the OIL LIFE MONITOR and nix the 3000 mile oil changes

http://finance.yahoo...mod=family-auto

You don't need to change your oil every 3,000 miles.

Here's a secret that mechanics don't want you to know: You really don't need to have your oil changed every 3,000 miles.

It's a waste of a precious resource -- not to mention money -- to take your car in every 3,000 miles or three months, experts say. On average, most cars don't need an oil change for 7,500 miles.

The folks who believe in 3,000 mile oil changes also believe you can't lose money in real estate. Urban mythology, or "my daddy said...."

The OLM algorithms were developed following thousands of laboratory hours testing oil at various miles of service. Most other car makers have a similar system but they cannot approach the accuracy of the (patented) GM system. We can only speculate why GM does not make the car buying public aware of the OLM as well all the other vehicle systems integration that has taken place since the 1980's and continues today.

Jim,

Millions of drivers NEVER open up the hood unless they see something coming out the engine department. Do you think they will care of oil life monitor?

[Cadillac Jim]

Many people won't open the hood as long as the car will go. I've seen unnecessary engine destruction over trivial things like a broken fan belt several times over the years. A high percentage of these cars are borrowed or rented, but I've seen people do it to their own property.

[JimD]

I recognize that the majority do not how or why the car goes. They simply require it to go. Maybe it's a good idea for them to leave the hood closed.

But they did learn to read a fuel guage and a speedometer. How hard can it be to learn to read an OLM or an engine coolant temperature guage??

[adallak]

A bit off topic, but anyway... Every time I need to reset time, oil life, etc. ... I have to open the manual and read the procedure up. Is my memory THAT bad, or others experience the same issue?

[adallak]

I recognize that the majority do not how or why the car goes. They simply require it to go. Maybe it's a good idea for them to leave the hood closed.

But they did learn to read a fuel guage and a speedometer. How hard can it be to learn to read an OLM or an engine coolant temperature guage??

Never happened to you? You see a definitely underiflated tire (that means some 10psi), approach the driver, tell him/her to pay attention and hear something like " Oh, I KNOW. Probably I should take care of it next week"?

[Cadillac Jim]

JimD: In my cynical observation, there is a broad spectrum of people and their cars, from the person who can be given a brand new Rolls Royce that they will be seen driving obliviously along with a dead cylinder the next week, and those who will drive a car 20 years and never allow a spot of oil on the engine, and everything in between. I think you can draw a classical Gaussian bell curve on that continuum and have a good cut at the statistics of this kind of thing. And, to get to the point, if you aren't on the high side of the curve, out in the top 10%, you aren't in a demographic that will remember what an OLM is from one week to the next.

[lothos]

My OLM is at 19% and I have oil for my next change. Won't pencil in time to do it until it gets down to 10-5%

[adallak]

JimD: In my cynical observation, there is a broad spectrum of people and their cars, from the person who can be given a brand new Rolls Royce that they will be seen driving obliviously along with a dead cylinder the next week, and those who will drive a car 20 years and never allow a spot of oil on the engine, and everything in between. I think you can draw a classical Gaussian bell curve on that continuum and have a good cut at the statistics of this kind of thing. And, to get to the point, if you aren't on the high side of the curve, out in the top 10%, you aren't in a demographic that will remember what an OLM is from one week to the next.

Jim,

Now when you mentioned the Gaussian bell, you have to educate us about the central limit theorem.

[Ranger]

My OLM is running about 50% right now. I'll take a look at the oil and if it looks good, I think I might let it run down to 40% before I buy eight quarts of Mobile 1.

You change the oil by "how it looks"? Might as well use the 3000 mile rule and forget the complicated computer algorithm.

[JimD]

....I think you can draw a classical Gaussian bell curve on that continuum and have a good cut at the statistics of this kind of thing. And, to get to the point, if you aren't on the high side of the curve, out in the top 10%, you aren't in a demographic that will remember what an OLM is from one week to the next.

Gathering that data would be a challenge!!

I would put my two daughters, my oldest granddaughter and myself on the far right side of that bell. And when my "girls" encounter an unfamiliar situation, guess who's phone starts ringing.

[JimD]

A bit off topic, but anyway... Every time I need to reset time, oil life, etc. ... I have to open the manual and read the procedure up. Is my memory THAT bad, or others experience the same issue?

Your memory is probably crammed full of the info you use every day on the job. As long as your memory tells you to "open the manual", you have nothing to worry about.

[adallak]

A bit off topic, but anyway... Every time I need to reset time, oil life, etc. ... I have to open the manual and read the procedure up. Is my memory THAT bad, or others experience the same issue?

Your memory is probably crammed full of the info you use every day on the job. As long as your memory tells you to "open the manual", you have nothing to worry about.

:D

[Cadillac Jim]

Ranger - don't take casual remarks too seriously. In the old days I used the smell to gauge when oil had accumulated too much from blowby to provide corrosion protection and such but I haven't done that in many years now. I really have no idea what I would do, but I would start with the smell test. If it passes that, perhaps an oil analysis while the OLM reads 50%, 40%, etc. would be educational for us all. Has anyone here ever done that?

[JimD]

....perhaps an oil analysis while the OLM reads 50%, 40%, etc. would be educational for us all. Has anyone here ever done that?

Yes. GM powertrain engineers did that and more. See post #3.

[BodybyFisher]

With the drop in ZDDP, if I owned a rubbing element NS, I would send a few of my oil changes into Blackstone, to compare the remaining ZDDP to the OLMonitors remaining life. I believe that would be an interesting exercise that would probably confirm that there is a safety margin built into the OLM

[Cadillac Jim]

That's what I was thinking, a 2010-2011 baseline using our old cars and new oil. I've ordered a pump and six tests with TBNs from Blackstone and will run a first test at 40%.

[JohnnyG]

We can only speculate why GM does not make the car buying public aware of the OLM as well all the other vehicle systems integration that has taken place since the 1980's and continues today.

Speculate is exactly right. It just drives me crazy that in their recent TV commercial, that Lexus(or one of them) gets to take credit for inventing the MR shock absorber. GM probably assumes that the motoring public is just too dumb to appreciate their efforts.....or they don't care.

The OLM is (was) a great addition to GM cars. Even one of my wife's freinds understood it immediately after I explained it to her, and it has saved her untold amounts of money during the ownership of her Buick. I say "was" since apparently in their efforts to push OnStar, the dash warning has been eliminated.

[Ranger]

At the risk of starting another war or getting beat up for this, I have to say that Blackstone makes a lot of money from oil fanatics like the guys on bobistheoilguy.com. It may make sense to a fleet owner, but to the average Joe, it just increases your oil change cost and gives you something to obsess about. Just change the oil when the OLM tells you to (or sooner) and you won't have any oil related failures. Forget looks, smell and Mileage, that's ancient "technology". We all know that.

[WarrenJ]

At the risk of starting another war or getting beat up for this, I have to say that Blackstone makes a lot of money from oil fanatics like the guys on bobistheoilguy.com. It may make sense to a fleet owner, but to the average Joe, it just increases your oil change cost and gives you something to obsess about. Just change the oil when the OLM tells you to (or sooner) and you won't have any oil related failures. Forget looks, smell and Mileage, that's ancient "technology". We all know that.

No argument here; my powder is dry.

Great common sense Ranger! Can I nominate you for czar of U.S. monetary policy?

Regards,

Warren

[BodybyFisher]

My point was

With the drop in ZDDP that has taken place, the Oil Life Monitors "OVERHEAD" is either LESS or now NON EXISTANT

With the rubbing element NS this is a serious problem, but NOT so serious with the rolling lifters

My point was, that the OLM needs a 'recalibration check' in my humble opinion. I would reset my OLM then run down to 40%, and then send a sample of my OIL to Blackstone to check that 40%. I am NOT implying to send EVERY oil change in for analysis ONLY a few to see how accurate the OLM is now that the ZDDP has been dropped. If you have a non rubbing element NS, you have less worries

There were times when I owned my 96, that it was 0% out and I didnt change my oil for a month past 0%, how dangerous is that now that the ZDDP has been dropped?

I am far from a fanatic, but with the drop in ZDDP, I would like to know what that overhead now is and when I should begin to panic. Of course if you change the oil on your rubbing element NS at 50% all the time, what I am saying is unnecessary, but if you go down to 0%, I think its important information

[JimD]

My point was

With the drop in ZDDP that has taken place, the Oil Life Monitors "OVERHEAD" is either LESS or now NON EXISTANT

With the rubbing element NS this is a serious problem, but NOT so serious with the rolling lifters

I believe API SG was the standard for the OLM algorithm for 199x Northstars and the OLM had 100% safety factor built in. In other words, the ZDDP would not be completely deleted/consumed until you ran the OLM down to 0% TWICE. But the OLM did not factor in that most of those engines would have one or two or more quarts of fresh oil added between oil changes.

Since those years the API service spec has "improved" to SH, SJ, SL, and SM. And yes, I am aware of the lower levels of ZDDP in "SM" oil as compared to "SG" oil. But I no longer worry about it.

My solution (FWIW):

Oil change now includes 4 quarts of either DELVAC or ROTELLA 15W-40 plus 3 quarts of 10W-30 SuperTech starburst "SM" oil. Final oil viscosity is 12.8W-36.7 with beaucoup ZDDP.

[BodybyFisher]

Good point Jim