GM Oil Life System

I've been trying to adhere to GM's reccomendation of following their Oil Life System. However, I just ticked over 4K miles with no "Change Oil" or such message. In my previous vehicles, I've changed oil every 2500 miles, so I'm itching to drop the oil out. I called my dealer and got his take on it, and he said I'd be better off just changing it like I normally do. I plan on switching to synthetic, changing it every 5K, and changing the filter every 2500.

My question is, does anyone know the parameters that the Oil Life System takes into account? I've heard everything from engine load, to average speed to the number of times that the engine ist started, but I was just curious. Thanks.

-Adrian

I use Mobil 1 Extended Performance 5w-30, 15,000 mile oil. 5qt jug from Wal-mart, for about $27, and Wix oil filter from a 4.3, cause it's longer, lets oil flow better, not so packed.
I change my oil every 12,000 mi, and the filter and rotate tires every 6,000mi. Been running synthetics for almost  600,000 miles, and never had an engine apart, nor one leak. Been running the Mobil 1 EP since it came out. That's when I went to 12,000mi oil changes.
Conventional oil has been around since forever. Step into the 21st century and use todays lubricants in todays vehicles.
My Onstar oil life monitor tells me I should be able to go 20-30,000 miles between changes.
Hope this helps.

wayne you seem to know what your talking about when it comes to synthetics. sorry to throw this thread off topic but is there anything i should know if i'm going to switch to synthetic? i've heard things about having to change your oil again in a shorter period when switching as the transistion makes the oil get dirty faster till you run it through a few times.. 

I always flush the oil system before switching motor oil, unless it's new. 
I don't  synthetics in my trannys, as I haven't seen the difference. Trans' don't  have combustion gases  to deal with like the motor does, nor have I seen any manufacturer make any major claims nor warrantys. I DO believe that they are every bit as good or maybe even better than Dextron III, but NO service tech had EVER tried to convince me that there is something better, unlike synthetic motor oils.
I personally believe that Royal Purple is the best motor oil out there, but they don't have a warranty. Fact is, NO BODY does but Mobil 1. I use their 15,000 mile product. Doesn't make cents to me not to.
I rotate tires every 6,000 mi, and that determines the frequency of oil and filter changes.
FYI: the Chevy dealer charged me almost $13/qt on the last filter change! Not again!

http://www.quakerstate.com/pages/programs/warranty.asp

So Quaker State says there oil is good for 4,000 miles WOW!. I'll stick with my  15,000 mile Mobil 1 EP oil, thanks.
But thanks for showing me that Mobil isn't the only company with a warranty, but there's is strict.
Are there any others? Any with a better warranty than Mobil? Is so, I'd be interested in trying it.
How 'bout trans' fluid?

good full synthetics are good for 10, 20 and some evern 30k miles.

It really depends on the type oil and driving condtions.

The oil life monitor makes an estimation based upon driving conditons, driving styles and various engine factors such as O2 sensor, MAF, MAP and IAT readings. It also knows the difference between stop and go traffic and crusing on the highway. For the most part its farily good and very conserative if using the type and grade of oil reccomended in the manual.

If your looking to maximize your oil life it really has abslotuly nothhing to do with number of miles. A more accurate measurement would actually come from number of hours your engine runs. The key factors for oil life are particulate counts and acidity (known as TBN). What is done in commercial applications (and what I do for the first year I own any car or truck) is I get a few oil analysis kits and send samples in at measured intervals. After a few cycles I can come up with a degradration curve that I use to estimate oil life. On a broken in engine (30-50k) using good synthitic (I use AMSOil) I go between 15,000 and 20,000 miles on average. On a newer engine its important to check more regularly as your cam(s), crank and other metal wear components will give off higher levels of metals as they settle in.

If you are using dino oil I wouldnt go more than 4-5k miles as the organic nature of the oil tends to result in higer acid levels very quickly even with modern acid inhibitors.

Finally get a GOOD filter, even if using cheap oil, your filter is the best way to protect your engine. Aside from acid, metal particles will wear on moving parts and can create long term damage. Make sure you have a good filter that filters out particles measured in microns and even when running oil for long periods (8k or more) change the filter at regular intervals (I change my filter ever 5-7k). Be sure to check the flow rate as well, some filters have really great filtering properties but do so at the cost of flow pressure. Low oil pressure can cause all sorts of problems.

In any case oil intervals of 2500 or even 3000 miles are antiquated and based on assumptions from almost 30 years ago. Technology has changed much since then. Unless of coure you are using the JiffyLube special oil, that crap isint fit for any modern engine and barely qualifies as oil.

For more information see: http://www.bobistheoilguy.com/

We've had great oil threads here.
 
The general concensus is that no matter if you you use dino or synth, a low-life oil filter will negate all your efforts.
 
Hope this helps.

OK, so what brand filters are good? I used to strictly use Fram, but now I hear that they are not any good, so what should I use?
 
 Thanks,
      John
 
 P.S.  My SS purchase has been delayed, I was actually able to sell my trade-in this weekend, so I'm taking care of that first, and looking at a couple of other SS's before I make the final decision.Got a lot more for the sale than the trade-in price, so that helps too...

I typically use K&N or AMSOil

What you are really looking for is some preffered desgin properties such as:

Metal, spring loaded bypass valve
high density, good flowing filter element
Strong support for filter element (better filters have support that goes for the lenght of the filter. Some only support the top and bottom causing the filter to collapse with age)
Solid gasket desgin as part of the filter not just glued on top
Well machined thread bore that decreses cross threading.
Rolled (as oppsed to pressed) lip on the end of the filter.

Also for all 95+ monte carlos (with the excpetion of the DOHC and the 3.9 60v6) go for the filter for the 4.3 v6 found in Blazers and many other v6 GM truck engines. The size and thread are excatly the same. The filter is longer helping with heat dissapation and providing a larger filter element.

On 2nd gen w-bodies (particuallry the 3.8 equiped cars 00-05 SS's) the clearnce for the larger filter is close but it will fit.

Fram used to be good. WalMart took care of that. Now they are bottom of the list. Most people say Wix is best, and if you cut one open, you'll see why. I believe any "best" quality will be adequate, as there really isn't that much of a difference. Just don't buy the cheapest filter you can, and Fram is it right now.\
AND, if you're running a 3.8L, put in a filter from a 4.3L, as they are almost an inch longer, and flow better than the shorter filters. Same amount of paper, just not as compressed.

I think I worry more about my oil and filter in the course of the day then I do anything ellse.  I have to agree with a lot of things I have read here but I just want to add a few somthings.  In my oppinion synthetic oil is the only way to go.  It got a bad rap back in the day becuase people were putting it into high milage cars and they got oil leaks.  Well this is becuase synthetic oil molecules are smaller then conventional oil.  As a result it would find it's way through cracks that conventional oil couldn't.  This is good news for most of us though becuase if the oil has smaller molcules then it will protect better by getting into areas conventional oil can't.  I personally would suggest castroll syntec but the warrenty sounds pretty convincing with that mobil brand.  Royal purpel and amsoil are good too.  As far as the Quakerstate goes PLEASE let me cuation you.  If your going full synthetic great but if not your sending your engine to an early grave.  Quakerstate and Penzoil both use the same crude from the same oil reserves in the north east part of the country.  This oil has a really bad caracteristic of seperating.  When this oil's molecules pick up dirt the clean molecules force the dirty ones to the outside perimiter.  This cuases sludge to build up very quickley and attatch itself to the walls of the engine.  This cuases higher heat, increased wear and bad gas milage.  As far as filters go the magic word is "micronic".  Any brand that offers a micronic filtration is going to be what you want becuase the smaller weaving catches more particles and keeps the oil cleaner longer.  The two brands I would suggest are WIX and Purealator.  I use the Purealator micronic becuase of all the test results I have seen.  I know it's long but I hope it helps.

Mobil 1 Full Synthetics is the best ...  I think they run that in the Corvette

quote:

ORIGINAL: LONESTARSS

As far as the Quakerstate goes PLEASE let me cuation you.  If your going full synthetic great but if not your sending your engine to an early grave.  Quakerstate and Penzoil both use the same crude from the same oil reserves in the north east part of the country.  This oil has a really bad caracteristic of seperating.  When this oil's molecules pick up dirt the clean molecules force the dirty ones to the outside perimiter.  This cuases sludge to build up very quickley and attatch itself to the walls of the engine.  This cuases higher heat, increased wear and bad gas milage.

I have indeed switched to Quaker State Q Horsepower. There is less lifter/rocker noise, and pressure is consistently higher so far. Mileage initially went up, but with winter it's heading back down. I've documented all my mileage though, so next fall I should be able to make fair comparisons.

In regards to your caution of using petroleum-based Quakerstate products, I understand what you mean in reference to Penzoil. In my spare time, I drag race. I drive for a man who is extremely particular about his engine, and the only reason he doesn't run Royal Purple is that he doesn't feel it's worth it when you change it everytime you're at the track. He previously ran Pennzoil, and after one run, I noticed the pressure falling at the end of the track. I cut the engine, and we pulled the dipstick. The oil ran off of it like water, and after we dropped it, it had for sure seperated. Needless to say that was the last time we ran Penzoil. He switched to Quaker State, and even lauching at 7500 and shifting at upwards of 9K, it has always worked well. I also ran QuakerState in my previous car, and in my wife's car. I pulled the pan on my wife's '95 Lumina, and at 145K miles, it was surprisingly clean. There's no argument that synthetic can stand the test of time better than petroleum-based. What it comes down to is maintenance, and regual oil changes with quality filters.

Anyway, to put and "end" to this post, I will from here out ignore my GM's oil life system. Thanks for all the input.

-Adrian

Please check out my post in the engine and internals section as to what GM approves, you ALL will be suprised, as I was. Check out your owners manual to confirm my post. Then check out the back of your oil bottles.
http://www.montecarloforum.com/m_67855/tm.htm