Oil Life Monitor - Predicting Oil Life Remaining after X Miles Driven

[Probity]

Here's a softball general question for those more knowledgeable than me on GM's Oil Life Monitor (OLM) operation.

 

After many years I've moved from numerous F150's to a '24 Silverado 1500 WT CCSB with the 2.7. I know from experience with Ford (and have read it's the same with GM) that even if you're an infrequent driver and don't put a lot of miles on between oil/filter changes, if you go a full year w/o an oil change/resetting the OLM (regardless of however few miles you might have - 10 or 100 or whatever), the OLM will show "zero" remaining oil life at the end of the 1 year period. That's fine, I get why it does that, it is what it is.

 

I'm getting ready to take a ~2300 mile R/T in a week or so. I've had my '24 CCSB for ~4 months now (1/3rd of a year) and only have ~1200 miles in total on it at present. My OLM is showing 64% (about 2/3rds) remaining oil life. 

 

My thinking is - the OLM operation is weighted to some degree on time (versus strictly miles accumulated/engine rpms/engine hours/idle time etc), and that's the main reason I've "used up" about 1/3rd of my oil life over a 4 month period (1/3rd of a year) having only driven ~1200 miles.

 

My expectation (wild-ass guess) is that the ~2300 miles I'll soon be putting on over the course of a couple of days will maybe drop my remaining oil life to the ~40% range by the time I get home. Of course If I get caught up in a major interstate traffic jam with many idling hours running the A/C that's a different story.

 

What say you Chevy/GMC mavens?

[MidTNDenali]

43 minutes ago, Probity said:

Here's a softball general question for those more knowledgeable than me on GM's Oil Life Monitor (OLM) operation.

 

After many years I've moved from numerous F150's to a '24 Silverado 1500 WT CCSB with the 2.7. I know from experience with Ford (and have read it's the same with GM) that even if you're an infrequent driver and don't put a lot of miles on between oil/filter changes, if you go a full year w/o an oil change/resetting the OLM (regardless of however few miles you might have - 10 or 100 or whatever), the OLM will show "zero" remaining oil life at the end of the 1 year period. That's fine, I get why it does that, it is what it is.

 

I'm getting ready to take a ~2300 mile R/T in a week or so. I've had my '24 CCSB for ~4 months now (1/3rd of a year) and only have ~1200 miles in total on it at present. My OLM is showing 64% (about 2/3rds) remaining oil life. 

 

My thinking is - the OLM operation is weighted to some degree on time (versus strictly miles accumulated/engine rpms/engine hours/idle time etc), and that's the main reason I've "used up" about 1/3rd of my oil life over a 4 month period (1/3rd of a year) having only driven ~1200 miles.

 

My expectation (wild-ass guess) is that the ~2300 miles I'll soon be putting on over the course of a couple of days will maybe drop my remaining oil life to the ~40% range by the time I get home. Of course If I get caught up in a major interstate traffic jam with many idling hours running the A/C that's a different story.

 

What say you Chevy/GMC mavens?

I'm in a similar situation with 2k miles in 5 months.  Most of my driving is short trips less than 10 miles with a couple of 500 mile road trips included.  I'm also at 64% and think the system takes into consideration the type of driving I do.  Anyhow, I'm already planning to do oil changes every 6 months at 2k-2.5k miles.  Everything I read recommends shorter oil changes and top tied fuel in the hopes of improved reliability.

[Probity]

29 minutes ago, MidTNDenali said:

I'm in a similar situation with 2k miles in 5 months.  Most of my driving is short trips less than 10 miles with a couple of 500 mile road trips included.  I'm also at 64% and think the system takes into consideration the type of driving I do.  Anyhow, I'm already planning to do oil changes every 6 months at 2k-2.5k miles.  Everything I read recommends shorter oil changes and top tied fuel in the hopes of improved reliability.

Thanks. Yeah I considered (for about 5 seconds) changing oil/filter before my trip, but even with the initial 5w-30 oil from the factory I figured ~3500 miles cumulative on it after my trip isn't much to ask. I am a little curious what the remaining oil life will read at ~3500 miles, not concerned at all but just curious.

 

I know from experience with one of my Fords (a 2012 F250 gasser) that high ambient temps and prolonged idle hours can and does eat up remaining oil life on the OLM at a pretty good pace - got caught in a massive semi truck accident/traffic jam on I10 between Houston and Beaumont once, 6+ hours either at 1-3 mph or dead stop, high 90's/high humidity day, used the A/C a lot. Before the jam I had about 500 miles on the truck since I'd changed the oil, after the jam once I hit about 2500 miles total since my oil change I got the "Change Oil Soon" message. Initial reaction was WTH?, but then remembered my traffic jam time. 

[Grumpy Bear]

1988. That's the year GM introduced the OLM to their vehicles. What do you think they brought to the party? Did it double the life of the motor?  Or did it replace thoughtful operation. 

[repairman54]

My experience with the OLM in many GM vehicles has been in winter it drops faster with cold starts, idling, etc. In summer it doesn't drop as fast, but it will zero out at 7500 miles. I drive enough so I've never had the one year zero out. 

I've never done short mileage oil changes, always at 10% life is my routine. '99 Yukon taken to 200k miles and sold zero drivetrain issues. '11 5.3 Tahoe to 150k and traded in for my Silverado with zero drivetrain issues. All had towing duty also. 

Other than using the OLM, severe maintenance schedule followed and only full synth. oils. Dexos in the engines. 

Many GM cars taken over 150k, some over 200k miles also with the same routine. 

[Phantom 4D]

My OLM showed 29% at 4800 and some change. I have the 3.0 mini diesel in my Sierra. The owners manual says 7500 miles. I'm not sure what metrics the OLM is based on. Sounds like some research time. 

[newdude]

IMO, too many people have too much faith in these Oil Life Monitoring systems.  Anyone who 100% wants to follow an OLM or any extended drain interval should be sending in used oil analysis for a few oil changes to see how far the oil can safely be pushed.  TBN, additives depletion, etc.  

 

19 hours ago, Probity said:

Here's a softball general question for those more knowledgeable than me on GM's Oil Life Monitor (OLM) operation.

 

I know from experience with Ford (and have read it's the same with GM) that even if you're an infrequent driver and don't put a lot of miles on between oil/filter changes, if you go a full year w/o an oil change/resetting the OLM (regardless of however few miles you might have - 10 or 100 or whatever), the OLM will show "zero" remaining oil life at the end of the 1 year period. That's fine, I get why it does that, it is what it is.

 

My thinking is - the OLM operation is weighted to some degree on time (versus strictly miles accumulated/engine rpms/engine hours/idle time etc), and that's the main reason I've "used up" about 1/3rd of my oil life over a 4 month period (1/3rd of a year) having only driven ~1200 miles.

 

 

Mileage is one factor as GM I believe has set them up as of about 6-8 years ago to have the OLM zero out at 7500mi.  This change came as a result of the oil issues on the 2.4 Ecotecs from 2010-2017.  

 

Mileage aside, its engine revolutions, temperatures and time that dictate it the most.  Time of course being the 1 year countdown on vehicles not driven frequently.

 

Engine Oil Life System

 

 

This vehicle has a computer system that indicates when to change the engine oil and filter. This is based on a combination of factors which include engine revolutions, engine temperature, and miles driven. Based on driving conditions, the mileage at which an oil change is indicated can vary considerably. For the oil life system to work properly, the system must be reset every time the oil is changed.

 

 

18 hours ago, Probity said:

Thanks. Yeah I considered (for about 5 seconds) changing oil/filter before my trip, but even with the initial 5w-30 oil from the factory I figured ~3500 miles cumulative on it after my trip isn't much to ask. I am a little curious what the remaining oil life will read at ~3500 miles, not concerned at all but just curious.

 

 

 

I can think of many very valid reasons to drop the factory fill before 1500mi on the odometer.  RTV silicone washing, initial wear metals, etc.  

 

 

15 hours ago, Grumpy Bear said:

1988. That's the year GM introduced the OLM to their vehicles. What do you think they brought to the party? Did it double the life of the motor?  Or did it replace thoughtful operation. 

 

B.I.N.G.O.  

 

1 hour ago, Phantom 4D said:

My OLM showed 29% at 4800 and some change. I have the 3.0 mini diesel in my Sierra. The owners manual says 7500 miles. I'm not sure what metrics the OLM is based on. Sounds like some research time. 

 

 

See above.  RPMs, temperatures, time and mileage.  

[64BAwagon]

I was told by someone who worked at the Milford proving grounds that the OLM system is as described above and the numbers came from running spec oil and the appropriate  AC filter on engine dyno's. Many thousands of run time hours under varying conditions and many thousand oil analysis tests were used to create an algorithm for each engine type. A lot of this was done at the request of the EPA in order to reduce oil change frequency (supposedly) 

Personally, the way it was described to me  sounded like it was the bare minimum someone could do to operate the vehicle until the warranty ran out. Obviously certain designs and models were not as robust as they might have hoped and the stretching of oil life was a negative. 

 

Sorry for the lines, my computer is junk. 

Edited yesterday at 12:37 PM by 64BAwagon

[Grumpy Bear]

29 minutes ago, 64BAwagon said:

I was told by someone who worked at the Milford proving grounds that the OLM system is as described above and the numbers came from running spec oil and the appropriate  AC filter on engine dyno's. Many thousands of run time hours under varying conditions and many thousand oil analysis tests were used to create an algorithm for each engine type. A lot of this was done at the request of the EPA in order to reduce oil change frequency (supposedly) 

Personally, the way it was described to me  sounded like it was the bare minimum someone could do to operate the vehicle until the warranty ran out. Obviously certain designs and models were not as robust as they might have hoped and the stretching of oil life was a negative. 

 

Sorry for the lines, my computer is junk. 

 

You hit the 'strike though' button. LOL 

 

They have a reason, and that reason was the EPA. But that reason won't get you to agree to do it so......they make a story up you will do it for, $$$$....We are very predictable, selfish and irrational. 

 

Since the damage it causes takes so long to show itself and is internal where Joe Average will never see the warning signs in time to prove to himself it is not in his best interest the story they makeup is convincing enough to get sheeple to do it.

 

Human indifference to our fellow man makes this work. Joe Average doesn't care what happens to the next fellow who buys it. No incentive to do right by him is there. Not your money. Just get rid of it before it fails on YOU. Never realizing that we cold buy fewer in a life time and save even more $$$$. The irrational part. 

 

  Our short sightedness in not realizing that if our car last twice or even three times as long we use less than half the natural resources which includes that precious oil. We pollute less so we gain more freedom, create less poverty. It drives the cost down but that shrinks the profit and no board member wants that. 

 

But we want what we want. Even when we know it isn't in our best interest. Especially when we are blind to it. 

 

[Grumpy Bear]

13 hours ago, KARNUT said:

I must apologize. I had promised myself I wouldn’t engage in this stupidity going forward. Especially after the debate if people weren’t enlightened to the great scam. There’s no teaching. If the current administration is your preferred choice. There’s really nothing to teach. No more trying from me.

 

You misunderstand. I wasn't making a political statement. I was making an economic one. God told Samuel when Israel rejected rulership by God and demanded an earthly King that it wasn't going to go well for them. (1 Samuel 8, entire chapter) God gave humans the 'freedom" to choose self-rulership but not the ability to actually succeed at it. Jer 10:23 

 

6K+ years of human history under man's rule is recorded. Every conceivable government type has been tried. ALL have failed to do what government's job is. Unite and protect. Do we have a cure for death yet? How about something simpler, like cancer. Everyone feed, housed and disease free? Are we free from war and crime. Have meaningful work? We can't even keep a road paved or water clean, garbage picked up. This country's Constitution asserts the "All men are created equal". We treat each other horribly and anything but equal. Each and every person believes "good and bad" is as they see fit. And that is the problem. Everyone is the boss.  

 

It's what Satan told Eve. "You will become LIKE GOD, knowing good and bad". Gen 3:5. Who's job does that say it is to decide? Just asking....

 

I'm not in either camp Stan. 

 

 

 

 

 

Edited 5 hours ago by Grumpy Bear
correct double negative

[txab]

Personally, I'd dump the factory fill oil and start fresh. You've been breaking in an engine and cleaning out all the nooks and crannies  where stuff was left in the casting or allowed in during assembly. my .02

[Black02Silverado]

To me the OLM is also a way to make money for the manufactures.  People tend to listen to what their car tells them on average. When a light comes on to change oil most get it done when probably in the past they would drive until they needed to add oil or some other reason.

 

I personally change out the factory fill at 500 miles, then again at 1,500 and then at 3K. From there I go from what my used oil analysis tell me.

 

Also after the 500 miles I change out the differentials and transfer case.

[Grumpy Bear]

Dad told me my entire life that I throw away better oil than most people use as he leans on the fender of Uncle Bob's million-mile flathead. Bob shaking his head in agreement. I reply, "You say that like it's a bad thing". I practice what I was taught and what I verified by myself. One of those things was; even with the same vehicle and even with the same driver, the OCI will change with weather and over its life.  

 

 

[diyer2]

Thanks. Yeah I considered (for about 5 seconds) changing oil/filter before my trip, but even with the initial 5w-30 oil from the factory I figured ~3500 miles cumulative on it after my trip isn't much to ask. 

 

Oil is cheap in my opinion, best answer.

[KARNUT]

6 minutes ago, Grumpy Bear said:

Dad told me my entire life that I throw away better oil than most people use as he leans on the fender of Uncle Bob's million-mile flathead. Bob shaking his head in agreement. I reply, "You say that like it's a bad thing". I practice what I was taught and what I verified by myself. One of those things was; even with the same vehicle and even with the same driver, the OCI will change with weather and over its life.  

 

 

I shortened my oil change intervals because I drive less on the interstate and keep them longer. What’s perplexing is I just retired a lawnmower after 10 years. If my brother doesn’t pick it up before the winter I may fix this one. Like the last 3 I only changed the oil once in 10 years. The oil on the stick with the last one still looks clean. The first one at my brothers house still runs. The owners manual with the new one says change the oil after 5 hours. LOL. Not in this heat. Maybe when it cools off. Like usual I’m stating experience. Not a suggestion.