GM Oil Life Monitor - What Does It Measure ?
- Thread starter ChrisD46
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Others would be better suited to tell you what they monitor but I have found them to be very accurate. I live by the OLM. Saves me lots of $$ on oil and filters and my cars have racked up lots of miles with no lubrication issues.
Here is an information sheet I found useful when I bought my first OLM equipped GM:
http://www.gmgoodwrench.com/_res/pdf/OLS1.pdf
I have always followed the OLM in all my GM's, never any issues.
http://www.gmgoodwrench.com/_res/pdf/OLS1.pdf
I have always followed the OLM in all my GM's, never any issues.
Originally Posted By: marc1
Here is an information sheet I found useful when I bought my first OLM equipped GM:
http://www.gmgoodwrench.com/_res/pdf/OLS1.pdf
I have always followed the OLM in all my GM's, never any issues.
And still, there are those who are convinced that it is a "mileage meter" that does nothing more than count down the miles.
Here is an information sheet I found useful when I bought my first OLM equipped GM:
http://www.gmgoodwrench.com/_res/pdf/OLS1.pdf
I have always followed the OLM in all my GM's, never any issues.
And still, there are those who are convinced that it is a "mileage meter" that does nothing more than count down the miles.
Thanks for the replies (cool information sheet marc1) .
Bought a 2002 Chevy Trailblazer 4.2L I-6 used (my only GM product with OLM) . Curious if the OLM is calibrated for synthetic oil - or does it matter ? Lastly , do most folks just wiat until the OLM light goes off - or do they change oil at 10% ~ 15% left range ?
Bought a 2002 Chevy Trailblazer 4.2L I-6 used (my only GM product with OLM) . Curious if the OLM is calibrated for synthetic oil - or does it matter ? Lastly , do most folks just wiat until the OLM light goes off - or do they change oil at 10% ~ 15% left range ?
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I have found the OLM in our Uplander to be a little over zealous. But this OCI seems like its doing a better job. Maybe someone accidentally reset it last time? If you are going to follow the OLM I would change the oil no later than 15%.
I believe that pre-2006, the monitors are just mileage monitors, after that more info was posted earlier. Most 2005 run out about 5K. 2006 and above say to change within 600 miles of light coming on.
Originally Posted By: ChrisD46
What exact parameters does a GM Oil Life Monitor measure ? I know they spent large $$$ on research - just curious and are they fairly accurate ?
General Motors developed its Oil Life System in the 1980s. It introduced the system throughout its model lineup in the mid-2000s after years of experience and tweaking.
It is a clock counting down to zero. The clock when set has a predetermined number of engine revolutions. A Corvette with synthetic motor oil might be set to alarm after 15,000 miles of mild temperature 1,500-rpm highway driving. An Malibu might alarm after 7,500 miles of the same type of driving.
The oil life monitor penalizes certain driving conditions such as very hot or cold weather, stop-and-go driving, high-engine-loads, and high rpms. It subtracts the revolutions made by the engine AND additional points for these adverse events.
There is also an upper limit on mileage and time.
The oil life monitor is unaware whether or not conventional or synthetic motor oil is in the crankcase. It does not know about coolant leaks, a bad air filter, or a number of other conditions which would suggest more frequent oil changes or a need for repairs.
All of the other manufacturers use similar systems in some of their vehicles, while some simply measure time and mileage.
What exact parameters does a GM Oil Life Monitor measure ? I know they spent large $$$ on research - just curious and are they fairly accurate ?
General Motors developed its Oil Life System in the 1980s. It introduced the system throughout its model lineup in the mid-2000s after years of experience and tweaking.
It is a clock counting down to zero. The clock when set has a predetermined number of engine revolutions. A Corvette with synthetic motor oil might be set to alarm after 15,000 miles of mild temperature 1,500-rpm highway driving. An Malibu might alarm after 7,500 miles of the same type of driving.
The oil life monitor penalizes certain driving conditions such as very hot or cold weather, stop-and-go driving, high-engine-loads, and high rpms. It subtracts the revolutions made by the engine AND additional points for these adverse events.
There is also an upper limit on mileage and time.
The oil life monitor is unaware whether or not conventional or synthetic motor oil is in the crankcase. It does not know about coolant leaks, a bad air filter, or a number of other conditions which would suggest more frequent oil changes or a need for repairs.
All of the other manufacturers use similar systems in some of their vehicles, while some simply measure time and mileage.
Btw, GM did find that some of its OLS settings were "optimistic":
GM to reprogram some ot its OLS systems
GM to reprogram some ot its OLS systems
Last year I was just over a year but waiting on better weather and the OLM was giving me over 20%. I got an email from Chevy that I was over the 1 year time limit to change the oil. So I gathered that the OLM wasn't monitoring the calendar. I doubt it really matters if I change it at 350 days versus 400 days but I didn't wan t to void the warranty.
I have noticed that on long trips in the summer it doesn't change the OLM very much but this time of year I've lost a couple of percent in under 200 miles ... I guess the temperature is the cause.
I have noticed that on long trips in the summer it doesn't change the OLM very much but this time of year I've lost a couple of percent in under 200 miles ... I guess the temperature is the cause.
Originally Posted By: LargeCarManX2
I believe that pre-2006, the monitors are just mileage monitors, after that more info was posted earlier. Most 2005 run out about 5K. 2006 and above say to change within 600 miles of light coming on.
Pre 2006 oil life monitor on GM vehicles work the same as the newer ones. My 95 Buick has one and the manual tells you that it can come on as soon as 2k and as late as 7.5k. The earliest that it ever came on in my car was around 3.5k and at the highest verifiable mileage was 5.2k on another occasion. Once I passed well into 5k and it still hadn't come on, but I just changed the oil because I couldn't wait any longer. The normal average was around 4-4.5k due to my driving which was mixed city/hwy driving. But it was never exactly the same but somewhat predictable since I had the same driving routine for the most part.
For most early OLM the max limit was set to 7.5k and later models 10k and up. I don't know what the max limit now but its reliable. My sister lives my the OLM for her Pontiac G5 and I'm sure it takes here in the 7.5k range. No engine problems yet with close to 100k. If you want peace of mind use synthetic fluids but the OLM system has been around for awhile and seems to work.
I believe that pre-2006, the monitors are just mileage monitors, after that more info was posted earlier. Most 2005 run out about 5K. 2006 and above say to change within 600 miles of light coming on.
Pre 2006 oil life monitor on GM vehicles work the same as the newer ones. My 95 Buick has one and the manual tells you that it can come on as soon as 2k and as late as 7.5k. The earliest that it ever came on in my car was around 3.5k and at the highest verifiable mileage was 5.2k on another occasion. Once I passed well into 5k and it still hadn't come on, but I just changed the oil because I couldn't wait any longer. The normal average was around 4-4.5k due to my driving which was mixed city/hwy driving. But it was never exactly the same but somewhat predictable since I had the same driving routine for the most part.
For most early OLM the max limit was set to 7.5k and later models 10k and up. I don't know what the max limit now but its reliable. My sister lives my the OLM for her Pontiac G5 and I'm sure it takes here in the 7.5k range. No engine problems yet with close to 100k. If you want peace of mind use synthetic fluids but the OLM system has been around for awhile and seems to work.
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Originally Posted By: LargeCarManX2
I believe that pre-2006, the monitors are just mileage monitors, after that more info was posted earlier. Most 2005 run out about 5K. 2006 and above say to change within 600 miles of light coming on.
I can tell you from experience that that's not true. The first OCI in my '02 Burb (bought it uses in mid-2012) ran out to just over 5,000 miles, but that included a 750+ mile highway trip in late October, meaning the engine was under relatively light loads at 65-70 mph for 5+ hours in moderate temps (70s to 80s). The very next OCI went 4,500 miles with only our normal driving pattern of 12-15 mile highway trips with ambient temps in the 50s to 70s. I am on the third OCI and am doing a double OLM run as I am running PU. I did not note when the OLM first tripped, but I am at about 7,500 miles right now and expect it to run out at 9,000-9,500 miles.
I believe that pre-2006, the monitors are just mileage monitors, after that more info was posted earlier. Most 2005 run out about 5K. 2006 and above say to change within 600 miles of light coming on.
I can tell you from experience that that's not true. The first OCI in my '02 Burb (bought it uses in mid-2012) ran out to just over 5,000 miles, but that included a 750+ mile highway trip in late October, meaning the engine was under relatively light loads at 65-70 mph for 5+ hours in moderate temps (70s to 80s). The very next OCI went 4,500 miles with only our normal driving pattern of 12-15 mile highway trips with ambient temps in the 50s to 70s. I am on the third OCI and am doing a double OLM run as I am running PU. I did not note when the OLM first tripped, but I am at about 7,500 miles right now and expect it to run out at 9,000-9,500 miles.
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Originally Posted By: mrsilv04
Originally Posted By: marc1
Here is an information sheet I found useful when I bought my first OLM equipped GM:
http://www.gmgoodwrench.com/_res/pdf/OLS1.pdf
I have always followed the OLM in all my GM's, never any issues.
And still, there are those who are convinced that it is a "mileage meter" that does nothing more than count down the miles.
My Ford F150 has a 6 month or 7500 mile "mileage meter". With some form of software algorithm that reduces the oil life if E-85 fuel is used extensively.
Originally Posted By: marc1
Here is an information sheet I found useful when I bought my first OLM equipped GM:
http://www.gmgoodwrench.com/_res/pdf/OLS1.pdf
I have always followed the OLM in all my GM's, never any issues.
And still, there are those who are convinced that it is a "mileage meter" that does nothing more than count down the miles.
My Ford F150 has a 6 month or 7500 mile "mileage meter". With some form of software algorithm that reduces the oil life if E-85 fuel is used extensively.
Originally Posted By: Wilhelm_D
all of the other manufacturers use similar systems in some of their vehicles, while some simply measure time and mileage.
Oil Life Monitoring systems vary wildly by mfgr, everything from simple mileage reminders all the way out to actually measuring the oil directly.
The GM system is extremely well respected as a fine example, cost effective yet quite accurate. In our fleet trucks it results in nearly unlimited engine life if used with a high quality oil and filter. It even accounts for our stationary operations as well...
all of the other manufacturers use similar systems in some of their vehicles, while some simply measure time and mileage.
Oil Life Monitoring systems vary wildly by mfgr, everything from simple mileage reminders all the way out to actually measuring the oil directly.
The GM system is extremely well respected as a fine example, cost effective yet quite accurate. In our fleet trucks it results in nearly unlimited engine life if used with a high quality oil and filter. It even accounts for our stationary operations as well...
here is a good post from 2005 om the gm olm
http://www.bobistheoilguy.com/forums/ubb...0036#Post130036
http://www.bobistheoilguy.com/forums/ubb...0036#Post130036
Originally Posted By: wapacz
here is a good post from 2005 om the gm olm
http://www.bobistheoilguy.com/forums/ubb...0036#Post130036
This is what I was looking for. Thank you.
here is a good post from 2005 om the gm olm
http://www.bobistheoilguy.com/forums/ubb...0036#Post130036
This is what I was looking for. Thank you.
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