Oil life monitoring

[BamCam]

Not sure if there is anyone else on the forum that can confirm this but it appears the '14 oil life is drastically different from the previous model. When I was leasing the '12 GS I only changed the oil once @ 12,000 miles and the monitoring system still said 30% oil life. I thought this was crazy high for mileage but the manual stated under ideal driving conditions the oil change interval can greatly improve but recommended once a year minimum(this is when I changed it). I drive 75/25 highway and city so I chalked it up to my conditions and driving style. I also was not overly concerned since it was a lease and knew it was being given back. When I traded it in on my '14 it had 21500 miles and the system said somewhere in the area of 40%.

Now onto the '14 GS, I currently have 1900 miles on the car in one month and the oil life monitoring is already at 73%. At this rate the car will have between 5-6k miles when the system hits 30% and oil is changed. This definitely makes the monitoring system more believabl...IMO. Since I bought this one I would like to monitor (no pun intended) this oil use more closely.

Any ideas why such a large difference? New gen motor? New oil being used? Feedback as far as oil consumption from '11-13 owners and '14 owners might shed more light as well.

 

[NHRATA01]

Seems like GM has learned some hard lessons about pushing the limits on OCI's. The 3.6's were notorious for timing chain issues, partially due to poor QC but also partially due to inhibited oil flow to the chains from sludge build up. So one of their recall changes on the affected models was a more conservative (ie shorter duration) program of the OLM. Within the past year it's become known that GM is also having a similar issue on the N/A 2.4's - and no surprise one of their fixes was again to reprogram the OLM. I have not seen this come up on the 2.0's...yet. But it is from the same Ecotec family though granted the '14+ LTG was a revised design from the older LHU. I suspect part of the problem is on the older port-injected engines, 12K intervals was sufficient. However DI is more harsh on the oil, particularly with fuel contamination. GM powertrain probably didn't take this into account when switching from port to direct injection designs on the same engine.

IMHO, I change the oil around the 7-8K mark with a quality synthetic, both on my GS and the wife's 3.6 Traverse.

 

[SSJ455]

Wow, 12,000 mileoil change. On my 2013 GS I changed it twice since May 2013 when I bought it new. And I only managed 5200-5500 miles between changes. I don't mind, but that is nothing compared to 12,000 miles. I can't explain it.

 

[bbronner413]

Hey BamCam,

Please see the attached link/discussion here we've contributed to here: http://buickforums.com/forums/threads/34850-Oil-life-monitor?highlight=oil+life

I couldn't agree more and have experience the same or similar issue.... I went on to say that when I had my 2011 Buick Regal Turbo, it seemed the Oil Life Monitor was rather generous. Meaning the monitor slow to tick down the percentage, implying going about 7,000-12,000 miles between changes (in the summer). I actually think a Service Bulletin was posted to correct the lengthy intervals to a more realistic value.

Now in my 2013 Buick Regal GS, it seems the Oil Life Monitor is going down VERY fast. I got my oil change at 3,477 miles and at 4,036 I was on 84% left and now I have 4,877 miles with 59% left. This implies about every 34 miles it goes down 1% and seems that I'll need an oil change again at only 3,400-3,500 miles since the service. I know it is the winter months and the weather is cold but this is a massive discrepancy between the 2 year models.

Right now I think I have 3,200 miles since my last change and I'm already at 12% which sucks.

 

[Benzadmiral]

I've read here that GM has developed and applied a new algorithm to the OLM for the DI engines such as the 2.4, considerably shortening the oil change interval. My 2011 CXL has already had that update, apparently, as the OLM is dropping by some 15% a month and will probably hit 10% when the current fill has about 4500 miles on it. That's 5 months of driving for me, so it should work out fine. (In fact the OLM is at 50% today, with about 2500 miles on the oil.)

My local dealer also says they recommend changing the oil, the AC Delco dexos1 synthetic blend, at 5000 miles; no mention of what the OLM says.

Once my 4 free oil changes are up, I plan to stick with a synth blend at a minimum, or a good synthetic, and change at 4500 miles/5 months.

 

[ralphhu]

Here is a March 20 2013 Regal GS Forum link posted by GottWhat to a very thorough explanation from a post by ls1gto.com of the GM Oil Life Monitoring system, who developed and patented it at GM, how it was developed, why it works flawlessly, and examples of how the same model of car can have different rates of oil life. I will also include a couple of paragraphs from ls1gto.com posting. But you will want to read the entire post to get a full understanding of and confidence in this system. This is my first post, so I hope I get it right.

http://buickforums.com/forums/threads/30313-Oil-Life-Change-Interval-and-Tire-Rotation

March 20th, 2013, 08:18 AM #8

GottWhat Full Member My Buick(s): 2011 Buick Regal Turbo (T06)

If you are worried about oil change intervals, get an oil analysis. That is the only way to know for sure. Also, the oil life monitor is pretty advanced. Here is a copy/paste from someone else in another forum:

Originally Posted by ls1gto.com

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.

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.
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.

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.

 

[NHRATA01]

Ralph, and again I just have to reiterate to take GM's word with a grain of sand (preferably not in the oil as that would be very bad 😉 ) regarding OCI's, as they now have 2 DI engine platforms where the TSB to address timing chain stretch involves a firmware update to the OCI to shorten oil life. Just saying...

 

[BuickTurbo]

I've never believed the oil life monitoring in any of the GM's I've leased or owned

The old check your oil dipstick for how bad it looks has always done right by me

 

[ralphhu]

When the author states that he knows personally from years of testing and has done thousands of oil analysis, and had worked directly with Dr Schwartz as this GM oil life monitor was being developed........I tend to believe that he is telling the truth. No one refuted his credentials or the veracity of his experiences in this. As I mentioned, to really understand the process, a person has to read the entire report. It is very technical. No one had negative things to say about that either. So I personally believe him. If there were any cracks in his report, I'm pretty sure there would be some who could point those out. But again, I understand that there are those who would stay on the safe side and go with what they consider the tried and true method. It is much cheaper to change oil than to buy and install replacement engines. I just thought the report did a pretty thorough job of explaining the whole process of how engine oil works, including additives. I am coming from a place of pretty much zero knowledge of things like that. 🙂

 

[Walt G]

I thought I'd bring this thread back to life with some observations of mine.

First of all, I 'was' one of those '12 GS owners with an oil life monitor that was ticking down VERY slowly. I was at about 14,000 miles between oil changes based on the OLM. I keep my cars a long time, so no matter what the OLM said, I changed at 5000 miles, but I didn't reset the OLM so that I could see when it would finally say I was due.

However, at about 8000 miles I put in a Trifecta tune. That tune reset my OLM to 100% (I didn't realize it would do that). No big deal. But my interesting observation is that my OLM is now ticking down much faster than before. It's headed for 5-6K life instead of 14k.

Now I'm pretty sure that Trifecta isn't 'tuning' the OLM, but I'm pretty sure that they take the 'latest and greatest' base GM calibration and tune from there (not touching the OLM). That tells me that GM has updated the '12 Regal's OLM calibration, but has NOT done a recall for it like they did with the 3.6 DI engine (maybe this is known and it just missed me).

If you've got an OLM that is ticking down very slowly, I wouldn't trust it (as it seems that even GM doesn't trust it and has changed it). I'm not sure if a dealer would reflash your car under warranty if you complained that the OLM is counting down too slowly, but you can always get a Trifecta tune, and that solves the OLM problem, and makes the car just a lot better in all of the well documented ways as well.

 

[GRRR8GS]

I would only use the OLM as a guideline. I have it in 2 GM's and its not my deciding factor to change oil. I don't think for the cost of an oil change that there is any cheaper engine maintenance you can do. For peace of mind the old guidelines of every 5000 miles are usually pretty close and safe. In most of Canada I would say twice a year is the minimum. Spring and Fall. The large temperature changes cause more condensation inside that can't be good for your engine IMHO.

 

[Mackiesback]

10-14,000 miles between changes is nuts.

Am I going to trust little LEDs or 40 years experience. These are direct injected engines as well, which is even more demanding. I am doing it every 5k regardless of the moniter, and only because Dexos is semi-synth.

If this were a lease, I might care, but I gotta try and make this thing last past the payments, and I drive 25k a year.

 

[Benzadmiral]

I recently had the chance to do a test of the OLM in almost all highway driving. The dealer changed my oil and reset the monitor to 100%. I then left on my trip to Amarillo, TX, a round trip of some 2000 miles, a week later with 98% on the oil life. Two days out, two days there (with city driving), and two back, nearly all highway, warm weather conditions, 60-75 mph for long stretches. I expected the OLM to drop more slowly than it normally does; th eOLM in the V-6 3800-powered Park Avenue dropped much more slowly on highway runs.

Nope. When I got back I saw 70% oil life remaining. Two thousand miles is about what I drive in two months, and the oil life drops by 14% a month in my normal 75% city driving. So the OLM is recording that I've used 28% of the oil's life in 2 months of driving, but crammed into just 6 days.

I'll have the dealer change the oil again in 2 months, when I should have about 4200 miles on it.

 

[qwk93ta]

I don't like to OLM, I change my oil every 5,000 miles with synthetic oil, usually Mobile 1.

 

[GottWhat]

For those that do not "like" or follow the OLM, I strongly suggest getting an oil analysis. Here is where I get mine: http://www.blackstone-labs.com/

Their standard test is only $25 +$10 for TBN analysis and can more than save that much if you start extending your oil change intervals.

This way, you can at least base your decisions on evidence/fact and maybe you will save money and time (which is even more important than money).

 

[Walt G]

The reason I brought this thread back up was because it seems there is evidence that GM made a running change to the OLM algorithm sometime during MY2012, and that change appears to have cut the oil life about in half (at least for the 2.0 turbo engine).

That explains why some are saying they are getting really long oil life, and others are not.

I don't think GM would have made such a big change unless they found a problem with the original long oil life. So, if you are going to trust the OLM, you've got to ask yourself, do you trust the original calibration of the OLM, or the updated one that cuts oil life about in half? And only owners of MY'12 turbo cars that have not had a software update need ask this question, based on the user experiences posted here.

My guess would be that GM got it right the second time after they revisited the OLM when 3.6 D.I. engines started to break the timing chain.

 

[NHRATA01]

The reason I brought this thread back up was because it seems there is evidence that GM made a running change to the OLM algorithm sometime during MY2012, and that change appears to have cut the oil life about in half (at least for the 2.0 turbo engine).

That explains why some are saying they are getting really long oil life, and others are not.

I don't think GM would have made such a big change unless they found a problem with the original long oil life. So, if you are going to trust the OLM, you've got to ask yourself, do you trust the original calibration of the OLM, or the updated one that cuts oil life about in half? And only owners of MY'12 turbo cars that have not had a software update need ask this question, based on the user experiences posted here.

My guess would be that GM got it right the second time after they revisited the OLM when 3.6 D.I. engines started to break the timing chain.

My thoughts exactly 🙂

 

[tjjohnson91]

I just change mine every 3500 miles. I don't believe you should run it for 7k miles for every change

 

[IceMan2]

Change all three of my new GM cars every 5,000 miles+the Harley whether they really need it or not. Works well for me...and they all run strong & happy.
IceMan2