# Engine oil change intervals



## ShoddyHog (May 17, 2006)

Well, I've picked over the book, and from what I can tell by GM standards I have to replace my engine oil when the light comes on or once a year. As I'm sure most of you do, I'd prefer to stick to a more routine schedule, and was wondering what others do.

I've always subscribed to the idea that in some cases a change at every 3k is required, but for a lot of cars that can be extended. In my case, my Goat has been driven all highway and a little light city traffic, and I expect that to be the same the entire time I own it.  There's not a ton of dust in my area, and other than the last couple days, the heat is usually not excessive. (St. Louis area) I've also decided to run Amsoil.

Given those conditions, I have no problem with changes every 5k. I'm currently at about 7,200, and the first oil change was at about 3,200. The Mobile One the dealer installed is still as clean and clear on the dipstick as it has the entire time I've owned it, and if I've burned any in that 4k, it can't be more than a 1/4 quart or so.

Gerry


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## Groucho (Sep 11, 2004)

I use Mobil1 and K&N oil filters, and typically change my oil every 7500-8000 miles.

The "every 3000 miles" paradigm is long outdated. If you do it that often you're just throwing money away...but whatever.

At that rate I'd be changing my oil every 2-1/2 weeks.


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## GTO JUDGE (May 14, 2005)

*I too use Mobil 1 and K&N... I change at 5K and rotate the tires at the same time. I do both town and highway driving. I suppose if I were only doing all highway / turnpike driving I'd go a little longer, but 5K is my interval.*


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## robo282 (Jun 21, 2006)

*Oil Change*

Advice: Don't tell me some thing bad!
1st change at 500 miles: use Mobil1& K/N
I am changing it tomorrow at 3300 miles, and it's dirty?


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## Blueguy (May 22, 2006)

With my GP, the oil life is determined by temperatures and RPMs (may be some other factors as well). Pretty good way to gauge the life of oil. Certainly much better then an arbitrary number like mileage. I'm guessing all GM oil life meters are calculated the same way.


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## GTO JUDGE (May 14, 2005)

robo282 said:


> Advice: Don't tell me some thing bad!
> 1st change at 500 miles: use Mobil1& K/N
> I am changing it tomorrow at 3300 miles, and it's dirty?


*It ought to be dirty, you put just about 3k on it. Where you drive it will effect the amount of contaminates in the oil. You may think you are getting no dirt in the oil but it finds it's way in there. You're ok.
*


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## Gpr1200r (Jul 1, 2006)

My opinion only......change your oil as often as your cashflow allows......All of my vehicles....38 Scarab included get Mobil 1. I have used Mobil 1 on all my engines and will continue to use it. I have a 98 Ranger that I use for towing at the boatramp w/77K on it and the leak down is way below the average. Mobil 1 should be sending me money.....Yeah....in my dreams....


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## enjracing (Jun 7, 2006)

seriously, with synthetic...........as long as it is no more than 10,000, your fine. especially if you don't beat on it with high rpm and high temps. i had a 95 5.0 that i bought new and used syn the whole life and chamnged the oil every 10,000 and when i took it apart to build a blower motor out of it, it looked like it was new. no wear, no sludge, nothing. i could even see the original factory cross-hatching on the cylinder bores. it was amazing.


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## ShoddyHog (May 17, 2006)

robo282 said:


> Advice: Don't tell me some thing bad!
> 1st change at 500 miles: use Mobil1& K/N
> I am changing it tomorrow at 3300 miles, and it's dirty?


Like GTO Judge said...I wouldn't worry about it. When I went out to take the picture below, I realized that the oil IS dirty, so my statement about it being as clean and clear as it was when changed was an incorrect statement. I should have said something like "pretty darn good" or "pretty darn clean".

Here's the picture I took. It's not the best, but its the best I could do in this heat. I probably sweat out a gallon just takin' this picture :cheers

This oil has over 4k on it now.


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## ShoddyHog (May 17, 2006)

Groucho said:


> I use Mobil1 and K&N oil filters, and typically change my oil every 7500-8000 miles.
> 
> The "every 3000 miles" paradigm is long outdated. If you do it that often you're just throwing money away...but whatever.
> 
> At that rate I'd be changing my oil every 2-1/2 weeks.


Well, just bear with this old-timer. Some habbits are hard to break. I guess I shouldn't find it shocking that the dealer recommended 3k intervals...they do need to make money. I've got something like 180k or so on my Bonnie, drove the piss out of it, changed the oil every 4-5k, and it still runs like a champ...with conventional oil.

Perhaps I'm trowing money away using Amsoil too??? My initial instinct was that I want the best for the car, but maybe that is an over-reaction for someone who's not going to abuse the car or drive in extreme conditions.

How often did you rotate & balance? You seem to be the mileage king around here.

Gerry


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## ShoddyHog (May 17, 2006)

Blueguy said:


> With my GP, the oil life is determined by temperatures and RPMs (may be some other factors as well). Pretty good way to gauge the life of oil. Certainly much better then an arbitrary number like mileage. I'm guessing all GM oil life meters are calculated the same way.


Can I assume that you only change the oil when the light comes on? If so, how long does that typically take for you?

I grew up as a shadetree mechanic and became an aircraft mechanic. Every lube change I've done in my life has been based on miles, hours, or flight hours, so GM's way of determining when to change scares me a bit.

I don't really consider mileage as "arbitrary" if you consider climate, type of driving, and driver habits.

Gerry


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## Blueguy (May 22, 2006)

ShoddyHog said:


> Can I assume that you only change the oil when the light comes on? If so, how long does that typically take for you?
> 
> I grew up as a shadetree mechanic and became an aircraft mechanic. Every lube change I've done in my life has been based on miles, hours, or flight hours, so GM's way of determining when to change scares me a bit.
> 
> ...


Yes, or slightly before, depending on how much free time I've got. I start thinking about it when it hits 10%.

I may be wrong, but I'm 98% sure the manual says to go by the oil life gauge for oil change intervals. It does not say 3000 miles. I thought the GTO manual was the same. I haven't really kept track, but I believe it's between 5-6000 miles. 

I feel confident in going beyond that even, because when my car was built, dino oil was pretty much standard. Now with synthetics, oils hold up much better. 

I used to have a link to a website that took a Camaro and drove it around the country and had the oil tested every 1000 miles and would see how far they'd go before the oil was no longer within standard. They did this will Mobil 1 and I believe Amsoil (could have been Royal Purple). The Mobil 1 lasted well over 10,000. I think it went 14,000 before they changed it. They did change the filter about part-way through though. With the other oil, it went even further and I think they ended it at some point because it was getting kind of silly. One thing to keep in mind though, is they'd top off the oil to repace the oil that'd burn off or was used for sampling, so that'll extend the life a bit. I might see if I can dig that up again if you're interested. 

3000 miles isn't really arbitrary, but it is a poor standard to go by if you want a good way to estimate the life of an oil. Heat and RPMs are much more relevant. It just really wasn't feasable to have a computer keeping track of these things back in the day. But now it can easily be logged and calculated.


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## fergyflyer (Apr 18, 2005)

Consumer Reports did a test on both Dino oil and Synthetics on NYC taxi cabs. They put special engines in that they had carefully tested cylinder diameters and the weight of the pistons with rings, plus some stat with the bearings, but I'm not sure what it was.

They then only put certain brands in certain engines. They had 12 cars for each brand. 3 cars would get changed at 3,000, 3 at 6,000, 3 at 9,000 and 3 at 12,000 miles. They had either just under or just over 100 engines for this test. They ran the cars for 150,000 miles. Then they took the engines apart and weighed and measured for wear. 1 engine failed, and it was an engine that was changed every 6,000 mile. Their findings were, there was no difference that they could measure between the 3,000 and 6,000 mile engines. Between the 6,000 and 9,000 mile engines there was a slight difference on the dino oil cars but no difference on the sythetic cars between 3, 6, and 9,000 in engine wear. Between 9 and 12 there was signifigant enough difference that they could measure it and definately not recomend a 12,000 oil change interval for both synthetic and Dino oil. All of the 12,000 mile cars were starting to consume oil in the 1 qt every 1,000 to 2,000 mile range.

There was absolutely no difference between brands and only minor difference between dino oil and synthetic.


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## aintmisbehavinn (Feb 9, 2006)

With all this, I suppose changing every 3-5K Mobil 1 is fine for an everyday driver. However, traffic in Atlanta is more like LA, not sure if I want to chance it over 5.:confused


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## Blueguy (May 22, 2006)

fergyflyer said:


> Consumer Reports did a test on both Dino oil and Synthetics on NYC taxi cabs. They put special engines in that they had carefully tested cylinder diameters and the weight of the pistons with rings, plus some stat with the bearings, but I'm not sure what it was.
> 
> They then only put certain brands in certain engines. They had 12 cars for each brand. 3 cars would get changed at 3,000, 3 at 6,000, 3 at 9,000 and 3 at 12,000 miles. They had either just under or just over 100 engines for this test. They ran the cars for 150,000 miles. Then they took the engines apart and weighed and measured for wear. 1 engine failed, and it was an engine that was changed every 6,000 mile. Their findings were, there was no difference that they could measure between the 3,000 and 6,000 mile engines. Between the 6,000 and 9,000 mile engines there was a slight difference on the dino oil cars but no difference on the sythetic cars between 3, 6, and 9,000 in engine wear. Between 9 and 12 there was signifigant enough difference that they could measure it and definately not recomend a 12,000 oil change interval for both synthetic and Dino oil. All of the 12,000 mile cars were starting to consume oil in the 1 qt every 1,000 to 2,000 mile range.
> 
> There was absolutely no difference between brands and only minor difference between dino oil and synthetic.


New York cabs are about as rough as it can get. Those 9000 miles for them is probably 15,000 for anyone else.


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## ShoddyHog (May 17, 2006)

fergyflyer said:


> Consumer Reports did a test on both Dino oil and Synthetics on NYC taxi cabs.


You wouldn't happen to remember about when that CR article was? It almost seems like I've got some buried brain cells that tell me I read that article.

Thanks to you and the others for the good info. You're going to save me some time and money.

Gerry


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## Blueguy (May 22, 2006)

Just for clarity regarding the oil change in the manual for my GP.



> Your vehicle has an Oil Life Monitor. This feature will let you know when to change your oil and filter -- usually between 3000 miles and 7500 miles since your last oil change. Under severe conditions, the indicator may come on before 3000 miles. Never drive your vehicle more than 7500 miles or 12 months (whichever occurs first) without an oil change


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## ShoddyHog (May 17, 2006)

Blueguy said:


> Just for clarity regarding the oil change in the manual for my GP.


I should have noticed that you have a GP...just spent a good hour or so trying to figure out where it tells me how much life I have left on the oil, and as far as I can tell, there is no way to find out on the GTO.

Here's the entry in the GTO manual...

Engine Oil Life System

When to Change Engine Oil

Your vehicle has a computer system that lets you know
when to change the engine oil and filter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil is
changed.

When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary .A Service Engine Oil message on the trip
computer display will come on. See Trip Computer
on page 3-33. Change engine oil as soon as possible
within the next 600 miles (1 000 km). It is possible that, if
you are driving under the best conditions, the oil life
system may not indicate that an oil change is necessary
for over a year. However, the engine oil and filter
must be changed at least once a year and at this time
the system must be reset. Your dealer has GM-trained
service people who will perform this work using
genuine GM parts and reset the system. It is also
important to check engine oil regularly and keep it at
the proper level.


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## aintmisbehavinn (Feb 9, 2006)

Hog, is this for the LS1 or 2? It seems like mine specifically stated every 3000 miles and I didn't know it had the electronic reminder. Maybe I don't have it activated, I have never reset, 10,000K on 06. :willy:


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## DrFix2Fly (Oct 27, 2004)

I would suggest that an engine, LS1 or LS2 is expensive. Oil is relatively cheap. With synthetic a reasonable milage to change it is at 5,000 which is a good time to rotate your tires as well. I really think that if you change your oil regularly and add some fiber to your diet, both car and driver will be happier and things will flow better.


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## ShoddyHog (May 17, 2006)

aintmisbehavinn said:


> Hog, is this for the LS1 or 2? It seems like mine specifically stated every 3000 miles and I didn't know it had the electronic reminder. Maybe I don't have it activated, I have never reset, 10,000K on 06. :willy:


I have the '06 M6 w/LS2....page 5-16 in the manual. I haven't read every page cover-to-cover, but the first thing I did was to look at the service intervals to make darn sure I stay in compliance with the warranty. I still have not found reference to any mileage recommendation.

I also don't think there's a way to de-activate the system, so the computer probably just doesn't think you need to change yet. The DEALER, however, recommended every 3k.


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## fergyflyer (Apr 18, 2005)

ShoddyHog said:


> You wouldn't happen to remember about when that CR article was? It almost seems like I've got some buried brain cells that tell me I read that article.
> 
> Thanks to you and the others for the good info. You're going to save me some time and money.
> 
> Gerry


I want to say it was in 99, but may have been as late as 2001. I'm not a big fan of CR, but this article was really interesting. 

I'm typically changing oil at 1000-1500 for the first oil change and then every 5-6000 thereafter. I've gotten 300,000 out of motors doing that on dino oil. I never go more than 6 months without changing it though. My father was involved in the oil industry and was an API engineer. He always said time is more important than miles, and 6 months was his limit. This was in the 80's and oils have gotten better, but I still stick with the 6 months. In Groucho's case though he'd probably say forget time. There are exceptions to every rule.


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## ShoddyHog (May 17, 2006)

fergyflyer said:


> I want to say it was in 99, but may have been as late as 2001. I'm not a big fan of CR, but this article was really interesting.
> 
> I'm typically changing oil at 1000-1500 for the first oil change and then every 5-6000 thereafter. I've gotten 300,000 out of motors doing that on dino oil. I never go more than 6 months without changing it though. My father was involved in the oil industry and was an API engineer. He always said time is more important than miles, and 6 months was his limit. This was in the 80's and oils have gotten better, but I still stick with the 6 months. In Groucho's case though he'd probably say forget time. There are exceptions to every rule.


Yeah, I think each individual will find their own "comfort zone" on this issue. I've purchased new cars before, and even if I got an Accura TL for more than the Goat costs, I wouldn't be near as anal about it as I am with the Goat. This thing is special.

I have no idea what the term "dino" means, but I know it is what I call "conventional" oil. I've got 180+ on my Bonnie, and I don't even have any notion to do a leak-down test on that thing. I runs like a raped ape, and has been on dino the whole time. Poor gal feels neglected at this point...I've driven her once in the last two months. That's OK...Bonnie gets some TLC this weekend after the cold front moves through.

Gerry


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## ShoddyHog (May 17, 2006)

fergyflyer said:


> I want to say it was in 99, but may have been as late as 2001. I'm not a big fan of CR, but this article was really interesting.


OK...I'm sure that's the same artcle I read, and came to the conclusion that if I changed the oil on my dino cars by 5k I'd be safe.

If you care to explain, why do you dislike Consumer Reports? I've subscirbed for damn near 20 years or so, and have found it to be a good source for information on upcoming purchases. In particular, their car buying guide will save people THOUSANDS of dollars if they follow what to do vs. just going into a dealer and taking sticker price. In that area alone, I'd say CR has saved me at least 5 grand over the years.

Feel free to PM me if you're not comfortable discussing it here.

Gerry


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## fergyflyer (Apr 18, 2005)

My issue with consumer reports is they tend to gloss over problems in Japanese cars but not in American cars. The last generation Acura TL is known for having transmission problems, but you don't see that in CR. The Nissan Titan pick-up, 1st and 2nd year models used lots of oil (1qt for every 800miles is called normal by Nissan) and is still prone to water leaks, but you don't see that stuff in CR. They give the new Toyota Avalon a recomended yet people are having issues with the electronics in the car locking them out and it not starting as well. The Toyota 3.0L v6 had sludge issues and engine failures yet you never saw a black mark in CR for the engine in those models. Hondas all through the 90's had problems with power window regulators, but CR never gave them any type of negative marks. 

I know they get their data from consumers in their reliability sections, but some of it is pretty flawed IMO. The tests they do themselves seem to be top notch and the info on how to get the best deals is good. 

Dino refers to dinosaurs, the source of conventional oil. LOL


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## ShoddyHog (May 17, 2006)

fergyflyer said:


> Dino refers to dinosaurs, the source of conventional oil. LOL


He he...makes perfect sense :lol: 

Thanks for the info on CR too. I guess I never noticed that because I don't pay all that much attention to the car reviews except for every few years, and I had no idea those other cars had the problems.

I take CR with a grain of salt, knowing they are capable of mistakes, or having their reports deviate from the norm on occasion. Most of the time, however, I find them to be a good source of general info and guidance.

I still haven't read the review they did of the GTO, yet purchased one...so I do, at times, trust my own instincts :cheers


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## manicrodder (Jun 24, 2006)

I don't believe the taxi tests have much bearing for our application. They run almost constantly and have no cold starts where a considerable amount of engine stress occurs.


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## Subdriver (Dec 28, 2004)

ShoddyHog said:


> I have the '06 M6 w/LS2....page 5-16 in the manual. I haven't read every page cover-to-cover, but the first thing I did was to look at the service intervals to make darn sure I stay in compliance with the warranty. I still have not found reference to any mileage recommendation.


Gerry,
There isn't one. The manual should have words to the effect of changing the oil when indicated by the Oil Life Monitor, or annually, whichever comes first. Here is an ariticle discussing how long that usually lasts: GM Engineer States that Oil Change Intervals Average 8,500 Miles with Oil Life Monitors

When considering what oil to use, keep in mind that the LS2 requires an oil meeting GM Standard 4718M. There are no conventional oils that meet that standard. 

Even if you do decide to stick with the time honored 3k/3 month rule, using a better oil will result in lower wear internal to your motor, and higher quality synthetics have high levels of detergents which will keep your motor cleaner and more efficient over time. Take a look at how low the wear metals (such as aluminum, copper, iron, lead) are on these samples on a 99 Corvette with the LS1 motor:
Corvette C5 AMSOIL Series 2000 0w30 Used Oil Analysis Report :cheers


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## ShoddyHog (May 17, 2006)

Subdriver said:


> Gerry,
> There isn't one. The manual should have words to the effect of changing the oil when indicated by the Oil Life Monitor, or annually, whichever comes first.


Right. In my first sentence that started this thread I said, "I've picked over the book, and from what I can tell by GM standards I have to replace my engine oil when the light comes on or once a year." I only made that statement about intervals because (without looking back) I think someone implied that there were suggested intervals in the manual.

I've decided to run Amsoil, and to change at 6k ideal and 8k max. That's probably still a bit agressive, but what the heck. I'll spend an extra $50 a year for the best synthetic oil changed a bit early vs. OK oil changed at the edge of its life. Besides, I want to rotate the tires at 6k like the book recommends, so I can just do it all in one shot.

I'm stocked up and ready to go!


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## Subdriver (Dec 28, 2004)

I love that shelf. :cool


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