# Oil Life Monitor-Just a Repeating Program



## 6speed (Dec 7, 2011)

Here is the data from my little game I play with the % Remaining Oil Life Monitor & what I discovered. For Oil change 1, I didn't keep track in groups of 5%, so it is not posted. To me it looks like the computer uses a cyclical program based on miles driven ONLY in making it drop each 5% group I record. For 15% in a row, it averages about 103 miles per 1%, then for the next group of 5%, it averages about 96 miles per 1%. It repeats this pattern every time- for over 9,000 miles, oil change after oil change. I don't believe I could purposely drive this style & be as consistent as this pattern repeats itself. The % Remaining Oil Life Monitor has nothing to do with counting engine revolutions, engine starts, temperature, or driving style like people say. It is just a "phony" program being used to pretend it's keeping track of how "good" the oil is.





% Remaining Oil LifeAvg. Miles/Percent(groups of 5%)Avg. Miles/Percent(groups of 5%)Avg. Miles/Percent(groups of 5%)Avg. Miles/Percent(groups of 5%)100%Oil Change 2Oil Change 3Oil Change 4Oil Change 597%95%8889888890%10410310310485%9696959780%10310410410275%10410410410470%10310410410365%9596969660%10410410310555%10410410310350%10410310410345%9698969840%10310110410435%10410410410430%10310310410425%9595989520%10410310210315%10310310410410%1031041041035%96change oil at 9%9896


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## sciphi (Aug 26, 2011)

How consistent is your driving? The OLM will drop faster with quite spirited driving, and will run longer during the summer with gentle highway driving. Mine shortens up in the winter due to the cold starts. 

44 mpg on Fuelly is saying that your driving is mostly highway, and mostly the same routes. That would go a long ways to making it look like a simple mileage counter.


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## au201 (May 18, 2013)

So let me ask you this...why is everyone's different if it's just a mileage counter? My moms gmc terrain with the OLM (using hers cause she drives the most and I haven't had my car long enough) will go about 8000 miles in the summer and anywhere from 6-7000 miles in the winter because of colder temperatures and a lot more idling. 


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## Merc6 (Jun 8, 2013)

What year are we talking if I missed it in signature (on app)? 11-12 OLM =/= 13-14 OLM.


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## Jim Frye (Mar 16, 2011)

I think the anecdotal evidence presented is just that. Unless someone can provide documented proof that the OLM is just a mileage counter, I can't buy it. However, I do know that owners with cars like mine report a wide range of mileages recorded down to 5% oil life left for the same type of car with the same engine. What's the variable? They all drive differently on different routes on different sorts of geographies. I drive nearly all city routes and don't get anywhere near 9K miles for an OCI. I get 6,300 - 6,400 miles at 5%. Mine is low because the car spends a lot of time idling in a school pickup line too. Someone else with a car like mine gets close to 7,500 miles at 5%, and he drives short highway drives but with lots of hills. I'll wager that other Cruze owners here will chime in with more information that will disprove the above theory.


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## Jim Frye (Mar 16, 2011)

Merc6 said:


> What year are we talking if I missed it in signature (on app)? 11-12 OLM =/= 13-14 OLM.


His fuelly says it's a 2011 ECO Manual.


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## obermd (Mar 3, 2012)

Mine tends to drop about 10% for every 1,000 miles I drive. In the winter it drops a little faster and in the summer it drops slower. I've also noticed that the better my MPG the slower it drops. 2012 ECO MT.


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## jandree22 (Sep 19, 2011)

If it's a phony counter based on mileage alone, how do you explain any variation between different oil changes? Should it not be exact miles at every % interval? While I appreciate the painstaking effort to log this, not sure I'm convinced.

In my 2014 Eco, I do mostly city driving. I just got my oil changed at 10,108 and I'm now at 10,590... 482 miles. I'm at 94% OLM. 482mi/6% is *80.33*. As the OLM is calibrated differently in my 2014 than 6speed's 2011, if someone else with an '11 or '12 could contribute a similar calculation since last oil change to compare avg rate of OLM decline, that would be helpful.


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## au201 (May 18, 2013)

jandree22 said:


> If it's a phony counter based on mileage alone, how do you explain any variation between different oil changes? Should it not be exact miles at every % interval? While I appreciate the painstaking effort to log this, not sure I'm convinced.
> 
> In my 2014 Eco, I do mostly city driving. I just got my oil changed at 10,108 and I'm now at 10,590... 482 miles. I'm at 94% OLM. 482mi/6% is *80.33*. As the OLM is calibrated differently in my 2014 than 6speed's 2011, if someone else with an '11 or '12 could contribute a similar calculation since last oil change to compare avg rate of OLM decline, that would be helpful.


I'll find out on my 12 tomorrow once I get it back from the shop! Lol 



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## Jim Frye (Mar 16, 2011)

http://assets.cobaltnitra.com/teams...5efa6b30/975c7820afba1004895010145efa6b30.pdf

GM's Oil-Life System Improves Timing of Oil Change

Oil Life Monitoring Systems - Edmunds.com


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## Eddy Cruze (Jan 10, 2014)

My CRUZE dropped 2% on the way home from the Oil change?


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## revjpeterson (Oct 2, 2013)

Eddy Cruze said:


> My CRUZE dropped 2% on the way home from the Oil change?


I've noticed something similar - drop from 100% to 99% almost immediately upon pulling out of the dealership parking lot, followed by a very quick (10-25 miles) drop to 98%, after which, it seems to decline pretty much uniformly from that point on.


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## Blue Angel (Feb 18, 2011)

You guys all have too much time on your hands...


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## CruzeEcoBlueTopaz (Jan 5, 2012)

The Eco I drive is an early model 2012. I drive 90% highway miles. My OLM has always consistantly averaged 10% per 1k miles regardless of weather or engine fuel efficiency. I believe I read some creditable posts on this forum mentioning the possibilty of an OLM algorithm change for the late 12' early 13' models. I personally believe for my cruze the OLM is based on miles considering its never been effected by the use of different oil,fuel, temperature or engine efficiency. A few other members with vastly different driving conditions then me also share the same 10% per 1k miles.


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## Merc6 (Jun 8, 2013)

CruzeEcoBlueTopaz said:


> The Eco I drive is an early model 2012. I drive 90% highway miles. My OLM has always consistantly averaged 10% per 1k miles regardless of weather or engine fuel efficiency. I believe I read some creditable posts on this forum mentioning the possibilty of an OLM algorithm change for the late 12' early 13' models. I personally believe for my cruze the OLM is based on miles considering its never been effected by the use of different oil,fuel, temperature or engine efficiency. A few other members with vastly different driving conditions then me also share the same 10% per 1k miles.


Reason I asked 11-12 or 13-14. The 20% on dexos 1 was off on the 11-12's vs the 13 plus. I'll go check mine in a few minutes on break as I keep trip 2 as oil change. My 98 Buick OLM was trash, I could do 3 5k changes and never see it light up.


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## Blue Angel (Feb 18, 2011)

CruzeEcoBlueTopaz said:


> A few other members with vastly different driving conditions then me also share the same 10% per 1k miles.


I think it's safe to say that your driving style is pretty much optimum for getting maximum oil life; long usage spent with the engine warmed up since you drive so much every day.

As far as others go, I would not be surprised to see similar oil life out of most people's cars who get the oil up to a minimum temperature during most of their trips, somewhere above 212F. As long as the oil gets up past that temperature, any fuel and moisture contamination will have been "burned off". Since the coolant temperature of the 1.4T is regulated somewhere between 220-235F during light load cruising and this engine uses a coolant fed oil warmer/cooler, it is fairly safe to assume that the oil is getting above 212F any time the engine gets up to operating temperature.

For those people who are regularly taking short trips where the oil does not get up to temperature, they are the ones most likely to see reduced Oil Change Intervals suggested by the Oil Life Monitor. If the car is driven over a period of time without getting the oil hot enough, fuel and moisture build-up in the oil will start to break it down and consume the additive package.

These are my thoughts on how the process works anyway, and why people with different driving styles would see similar OLM output. I didn't actually read a GM OLM manual (if that even exists), but I do know a little about oil and what causes its service life to be limited.


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## Nano-Skiff (Aug 25, 2014)

2013 Eco - 2572 miles on the odometer and 9% oil life remaining. I have only had it a month now. I put all but 100 miles on it in that time. I guess the rest of the counting was from time instead of miles. It sat there at the dealership for a long time. I think it was about 15% oil life remaining when I bought it with 100ish miles on it.


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## Blue Angel (Feb 18, 2011)

Nano-Skiff said:


> 2013 Eco - 2572 miles on the odometer and 9% oil life remaining. I have only had it a month now...
> 
> ...It sat there at the dealership for a long time.


Great info, thanks!

While sitting for a long time it was probably started and moved around the lot many times without warming up. The OLM sees activity like this and moves the next oil change up appropriately. That fits into my thoughts on OLM activity above.


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## Nano-Skiff (Aug 25, 2014)

I'm pretty disappointed in myself really. I should have noticed while test driving and had them do an oil change for me. Why would I buy a new car with old oil? Oh well. Why would they sell cars with 2 keys and not make the 2nd one until the car was bought. Why would they sell a car with 2 recalls? Axle and coolant levels. I think they just like wasting my time and making me go back often.


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## MilTownSHO (Oct 9, 2013)

I have about 6900 miles since my last oil change on my Diesel, shows 7% left.

I drive 88 miles a day mainly highway and county back roads. Some hills, but I average about 47-48 MPG with a tune.

My OLM seems pretty consistent, it was always below 20% when I took it in for my 4 free oil changes.


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## 1988gmc355 (Jul 20, 2016)

@ChevyGuy


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## Eddy Cruze (Jan 10, 2014)

I just went 9 months and only put on 2000 miles. I was down to 20% on the OLM. Since mileage wasn't a factor here I am convinced it uses Time and or Mileage


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## Robby (Mar 1, 2013)

It uses running time per start, accrued mileage, actual time in days, ambient temperature at each start cycle, called a 'algorithm' among a few other parameters that I don't recall.

Rob


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## ChevyGuy (Dec 13, 2014)

This 3-year old thread got revived from the dead due to a discussion in another thread about OLM. I think this document is a pretty definitive statement about how the OLM works in current (2010-2017) GM cars. The other documents (cobaltnitra.com and Edmunds.com) are either laughably generic, or describes GM's actions around 2000.

Of course, other manufacturer are free to use their own system, but since this is a forum focused on the Cruze.


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## Eddy Cruze (Jan 10, 2014)

ChevyGuy said:


> This 3-year old thread got revived from the dead due to a discussion in another thread about OLM. I think this document is a pretty definitive statement about how the OLM works in current (2010-2017) GM cars. The other documents (cobaltnitra.com and Edmunds.com) are either laughably generic, or describes GM's actions around 2000.
> 
> Of course, other manufacturer are free to use their own system, but since this is a forum focused on the Cruze.


Pretty cool document and goes with what Robby said as well. Not too many people in this thread seemed to factor in time. Overall the OLM is very accurate


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