GM Oil life monitor-45,000 miles of data

[RhondaHonda]

I was always skeptical about the GM Oil life monitor so I made notes every time I got an oil change. I got a new 2012 Impala in March 2012. Each time I had the oil changed (company car) I noted the oil life remaining, mileage, miles on oil and average speed which I reset each change. Some days I do a fair amount of idling in this car with multiple short trips, city driving and it will run from 8 am to 4 or 5 pm and never get shutoff, others I drive 200-300 miles all on the highway only and have even taken a few 400-500 mile trips as well. I used the mileage on each oil change to calculate hours on the oil and posted the #s below.

In summary, no matter how I drive this car, it goes 93 miles per % on the oil life monitor, +/- 1%. So basically the oil life monitor in this car is a mileage counter and nothing more.

Impala oil change

6/13/12
7767 miles
Avg speed 21 mph
17% oil life remaining
370 hours on oil
93.58 miles per %

9/11/2012
14768 miles
Avg speed 24.9 mph
25% oil life remaining
7001 miles on oil
281 hours on oil
93.35 miles per %

1/5/13
Miles 22613
Avg speed 30.5 mph
16% Oil life remaining
7845 Miles on oil
257 Hours on oil
93.39 miles per %

5/2/13
Miles 30490
Avg speed 29.4 mph
16% oil life remaining
7877 miles on oil
268 hours on oil
93.77 miles per %

8/19/2013
Miles 37627
Avg speed 27.0
23% oil life remaining
7137 miles on oil
264 hours on oil
92.69 miles per %

1/14/2013
Miles 44693
Avg speed 28.0
25% oil life remaining
7066 miles on oil
252 hours on oil
94.21 miles per %

 

[SteveSRT8]

Not true, at least in our fleet.

It even accounts for our stationary operations. It is the farthest thing from a simple mileage counter...

 

[Voltmaster]

As I have said for long time here, most OLM really dont do much except for count milage.

my 2000 accord has maintaince required light that comes on every 5k. OLM is no diffrent except makes you feel more fancy. Specailly an American car, I'd only trust an OLM that is installed on a car that cost 60k+.

 

[mrsilv04]

What your OLM is telling you is that you're following a fairly typical routine, when it is looked at over a period of 7,XXX miles. To you, it seems random. Over a period of 7,XXX miles, you're doing the same things over and over.... and then doing the same things over and over from oil change to oil change.

As a result, your data looks quite similar.

The OLM's on the GM vehicles that I take care of are far from being a mileage counter. It shortens the oil life interval *significantly* in harsh cold winter conditions, but then it hardly moves when I'm travelling several hundred miles on the interstate in the summertime.

If you were in a harsher climate, you'd see it.

 

[mrsilv04]

Originally Posted By: Voltmaster
As I have said for long time here, most OLM really dont do much except for count milage.

my 2000 accord has maintaince required light that comes on every 5k. OLM is no diffrent except makes you feel more fancy. Specailly an American car, I'd only trust an OLM that is installed on a car that cost 60k+.



Maybe that is the way it works on *your* Accord.

Stop lumping everything together. That's flawed thinking.

 

[demarpaint]

Originally Posted By: RhondaHonda


In summary, no matter how I drive this car, it goes 93 miles per % on the oil life monitor, +/- 1%. So basically the oil life monitor in this car is a mileage counter and nothing more.

 

[Zaedock]

Originally Posted By: Voltmaster
As I have said for long time here, most OLM really dont do much except for count milage.

my 2000 accord has maintaince required light that comes on every 5k. OLM is no diffrent except makes you feel more fancy. Specailly an American car, I'd only trust an OLM that is installed on a car that cost 60k+.



You're incorrect.

Originally Posted By: mrsilv04

If you were in a harsher climate, you'd see it.


I have consistently seen longer intervals in summer than winter. My current oil life is 14% with only 6,000 miles on the interval. I usually average 7500+ in summer.

 

[threeputtpar]

Here is a way you can test your theory that's it's just a mileage counter.

Get your oil changed and then immediately head out on the interstate and drive 200 miles at a constant 70mph. If at the end of the jaunt your OLM goes down 2% then you have proof that you're correct.

The fact that all of your average mph readings are between 21 and 30 mph means that you don't have enough variability in your habits to come to a clear conclusion. If one of your OLM intervals was to be say 50 mph or greater and you still come up with 93 miles/% then I'd be more inclined to agree with you.

 

[FutureDoc]

I don't know about it being a mileage counter.

When my wife's Fit was driving in city traffic for her commute (Stop/go 5-35mph ave), it popped on every 6-7K, when we moved and it became a highway-only (100mi-1k+ weekend trip, 55-75mph ave) car, it stretched out to even 10K+. Right now, it is at 60% on syn-blend with 5,300 on that oil. I do not completely trust it with syn-blend in it so it will come out at 7K but I have seen it vary in very different driving conditions.

Not all counters might be the same, but I bet many tracking the gearing, mileage, and RPMs. Older OLM might be more set-mileage, but newer ones should not be... the CPU is too robust.

 

[kschachn]

Or let it idle in the driveway for three hours.

Originally Posted By: threeputtpar
Here is a way you can test your theory that's it's just a mileage counter.

Get your oil changed and then immediately head out on the interstate and drive 200 miles at a constant 70mph. If at the end of the jaunt your OLM goes down 2% then you have proof that you're correct.

The fact that all of your average mph readings are between 21 and 30 mph means that you don't have enough variability in your habits to come to a clear conclusion. If one of your OLM intervals was to be say 50 mph or greater and you still come up with 93 miles/% then I'd be more inclined to agree with you.

 

[Subdued]

So you're driving the car the same exact way from one oil change to the other, and you're expecting an OLM to somehow show different results from one OCI to the other?

Isn't this the definition of insanity?

 

[71Chevyguy]

It is way more complicated than that. You get the same results because like someone said your driving patterns are always the same. I had a Chevy Express Van that was driven regularly in NYC traffic and in the winter it would ask for an oil change at just over 2,000 miles of daily city driving. In the warmer months it would sometimes go to 4,000. It is def not just a mileage counter.

 

[widman]

My 2012 Grand Cherokee light has never gone off, so I don't know much about it, but the 2009 went off at 5000 miles unless I did a bunch of mountain driving, which here means mostly at 20-30 mph up and down dirt roads. At the next start the light came on if I had more than 2500 miles on it. So it was assuming that those 100 miles of mountains cut 2500 miles off the oil change.

 

[nepadriver]

let's say oci=7000 as default reset value


if (avgtemp < 40) && (MPG < 20)
then OCI=(OCI-50)
fi

Run that ever mile or two, have it go off no earlier than 3700 miles or whatever.Probably could do better one if I wasn't drinking. Onboard computer have all this data anyway

 

[RhondaHonda]

Originally Posted By: threeputtpar

The fact that all of your average mph readings are between 21 and 30 mph means that you don't have enough variability in your habits to come to a clear conclusion. If one of your OLM intervals was to be say 50 mph or greater and you still come up with 93 miles/% then I'd be more inclined to agree with you.


I will watch it the next time I have to drive interstate driving for more than 100 miles and report back. The 370 hours on the initial change compared to the ~250-280 on the others still working out to 93 miles/% really leads me to believe it is a mileage counter and nothing more.

I work out of the car so I leave it running when it is hot or cold and it gets sometimes hours per day of idle time. If the weather is mild and I can work in it with it off, I do but in St. Louis that is only a few months max per year but the OLM still doesn't show any variation.

 

[Clevy]

My charger is just a mileage counter and I set it myself. I can set it to whatever mileage I want and it displays time to change when the miles count down.
Same goes for tranny fluid and tire rotations.

 

[clinebarger]

My '06 Silverado Diesel OLM is a miles counter, Set at 10,000 miles, Read directly from the ECM with HP-Tuners, Changed it to 7,500 miles.

 

[NMBurb02]

The OLM on my '06 GP is definitely not a mileage counter. My driving varies greatly from short trip grocery getter one week to multiple 200+ mile roundtrip highway trips the next and the OLM ticks down at varying rates. The last OCI was set to run to about 9,000 miles to 0% and I am at 80% remaining on the current and will only go to 8,300 if I maintain my driving style from the past 1,667 miles.

 

[95busa]

The olm on my E350 seems very responsive. I drove straight interstate for 1800 miles, it changed less than 10%.

 

[demarpaint]

Originally Posted By: 71Chevyguy
It is way more complicated than that. You get the same results because like someone said your driving patterns are always the same. I had a Chevy Express Van that was driven regularly in NYC traffic and in the winter it would ask for an oil change at just over 2,000 miles of daily city driving. In the warmer months it would sometimes go to 4,000. It is def not just a mileage counter.


I always said NYC traffic was hard on an engine and hard on oil. I wonder how many people are using dino oil under conditions like yours and dumping it every 5K, or synthetic oil every 10K miles because of blanket statements like dino oil is good for 5,000 miles and synthetic oil is good for 10,000 miles. Based on your OLM that would be a formula for disaster. Those numbers are an eye opener.