A Look at GM's Oil Life Monitoring System

[NavyDood]

Originally Posted by cruznls

We like to "Change the Filter" every 3000 to 5000 miles then
top off the oil...

Which is a very good idea with your average off the shelf filter.

My point/counterpoint on these topics is mainly about the oil. Today's off the shelf oils should go the length of the
OLM with ease. Other oils can surpass what the OLM tells you. Highly doubtful we will ever know what oil filter GM used during all their testing and research. But, i'm pretty sure it's safe to say they used a Delco filter.

I personally would only let two filters go the distance of the OLM. Those filters would be Amsoil Ea15k50 and Mobil1 M1-113. Any other filter I would highly recommend a filter change with a top off of oil at 50%. If you fall into the once a year category because you don't drive it that often, then one filter would be fine.

I currently have a Delco on the car. I am going to do an analysis when the oil is changed. On the upcoming oil change I am installing a Amsoil Ea15K50 with Mobil1 oil since we have a free oil change. I will let that go the distance of the OLM and do an analysis at that oil change. The oil change after that I am going to use Amsoil signature series with an Amsoil Ea15k50 oil filter.

[J Webb]

How does the alogorithm calculate cylinder pressure which adds pressure at all friction points, causing the depletion rate of zdp to be much faster. My oil life monitor with 8lbs of boost doesnt move any faster, although the car does. I'm honestly scared to trust it. At 8,000 it still reads 40%. Thats 8,000 haulin ass too. My L99 starts ticking a little more on start ups after bout 6,000. In stock form 8qts, oil cooler, low friction, I'm thinking !0,000 probably ok. I was hoping that I would see a difference in the oil life with the extra 200 horse. I didnt. I'm thinking I might want to change at 50%. Anybody else with extra boost know?

[Mr. Wyndham]

Originally Posted by J Webb

How does the alogorithm calculate cylinder pressure which adds pressure at all friction points, causing the depletion rate of zdp to be much faster. My oil life monitor with 8lbs of boost doesnt move any faster, although the car does. I'm honestly scared to trust it. At 8,000 it still reads 40%. Thats 8,000 haulin ass too. My L99 starts ticking a little more on start ups after bout 6,000. In stock form 8qts, oil cooler, low friction, I'm thinking !0,000 probably ok. I was hoping that I would see a difference in the oil life with the extra 200 horse. I didnt. I'm thinking I might want to change at 50%. Anybody else with extra boost know?

It takes into account a pre-determined value. The software doesn't know (outside of increased heat, etc) that you have a supercharger on the car.

[camaro2009]

good read... i only have 4200 miles and had car 7 months. OLM still says 71%. I was stressing whether or not, i was waiting to long. Growing up dad always drilled into my head( while laying under the 1979 Malibu 267cu in, V-8. Change oil every 3000 miles boy). Now i will wait until 5000 for the first oil change.

[J Webb]

Originally Posted by Dragoneye

It takes into account a pre-determined value. The software doesn't know (outside of increased heat, etc) that you have a supercharger on the car.

So what would be a good recommended interval? Do you think the ZL1 will have a different set of values? I guess its hard to guess, but if you had to, 6-8,000? You would think there would be a way of measuring load %.

[justmeron]

I usually wait till I get around 5%. Usually 5%-10% I schedule a visit for an oil change. About 1-2 times a year for me, pretty neat. It is still under waranty so even better.

[DUGG]

I used Mobil 1 in my '98 Z-28 and I put over 245,000 miles on it....and it never missed a beat. I usually changed it at 7500 miles. I use the same Mobil 1 and change it ever 7500 on my 2010. The only complaint that I have is that there should be an indicator showing HOW MUCH oil is actually in your car. Sometimes, I haven't lost a drop, and sometimes I'm half a quart low between changes at 7500 miles. What causes the difference? Heat?

[phenixdragon]

I have been arguing this with people for so long. Cars these days just last longer with oil. Oil is better, motors are built better, 3,000 miles was being dropped in the 90's. Even my 95 ///M3 was rated for changes at 15,000 miles. Funny though, I took my Camaro in a few weeks ago and they always keep writing 3,000 miles on the window take that I always take off right away. It kinda of makes me think the tech doesn't know what he is doing, but I think it's to have people still change their oil at 3,000 miles when not needed. More money for them.

[phenixdragon]

Originally Posted by DUGG

I used Mobil 1 in my '98 Z-28 and I put over 245,000 miles on it....and it never missed a beat. I usually changed it at 7500 miles. I use the same Mobil 1 and change it ever 7500 on my 2010. The only complaint that I have is that there should be an indicator showing HOW MUCH oil is actually in your car. Sometimes, I haven't lost a drop, and sometimes I'm half a quart low between changes at 7500 miles. What causes the difference? Heat?

Maybe because it doesn't all drain out?

[Tysen]

GM Fuels and Lubes? Gotta be hard to work there with all the snickers.

[BackinBlack]

Can anyone comment on the OLM ability to adjust when you store the vehicle six months at a time?

I change the oil the day before it goes into storage, but always wonder what happens as it sits in my garage for six month. According the the OLM, it doesn't degrade, not even 1%. But I don't think the OLM can check a calendar and realize six months of garage temperature cycling has occured from Nov to April. Or can it?

From my normal summer driving I've never seen the OLM lower than 80%, and it gets changed at the end of every season, but I'd still like to know more detail about the OLM ability to account for months of storage, if someone can comment.

With conventional oil I'd be changing before *and* after every eason, but with the synthetic I'm not sure what the storage does to it.

[Mr. Wyndham]

Originally Posted by J Webb

So what would be a good recommended interval? Do you think the ZL1 will have a different set of values? I guess its hard to guess, but if you had to, 6-8,000? You would think there would be a way of measuring load %.

The ZL1 will have an OLMS specifically tailored to it's engine specifications. That's one of the benefits the article referred to - is that the software can be modified for each vehicle it's used in to return the most accurate report.

As for a recommended interval...I don't know. It would interesting to see if anyone has done an oil sampling after an after-market supercharger was installed and compared the degradation to stock...But I just don't know - I'm far from an expert on engine lubrication. I just know what I've read about GMs OLM system.

If it were my car? I'd change at 25-50% until I researched and found a better answer/solution.

Originally Posted by BackinBlack

Can anyone comment on the OLM ability to adjust when you store the vehicle six months at a time?

From my normal summer driving I've never seen the OLM lower than 80%, and it gets changed at the end of every season, but I'd still like to know more detail about the OLM ability to account for months of storage, if someone can comment.

That's a great question, and one I'd love to know the answer to! Does the OLMS take into account rest time?

[superchris]

SO WHAT KIND OF OIL ARE YOU GUYS USING ON THE SS??!? TYPE/W

[NavyDood]

Originally Posted by J Webb

So what would be a good recommended interval? Do you think the ZL1 will have a different set of values? I guess its hard to guess, but if you had to, 6-8,000? You would think there would be a way of measuring load %.

Dragoneye pretty much covered it. If you want your own baseline so you know what your engine is doing, change the oil and do an oil analysis at 25% increments. In the end it may cost you the price of analyzing the oil four times, but at least you will have a baseline to go off of.