GM Offers Oil Life Monitor Information
- Thread starter Egg_Head
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Not sure why but I find how OLM's work fascinating. Not enough information to say with certainty but similar to the OLM in my 15 F150. Except Ford seems to think perfect oil use is 10k and 1 year and GM targets 7500k and 1 year.
I've read some of how the BMW OLM's work but I have not read anything on Audi or MB. Just has me wondering......
I've read some of how the BMW OLM's work but I have not read anything on Audi or MB. Just has me wondering......
Hmm. Makes me wonder if at some point they will have to add in a variable or loop that will attempt to cut down on service visits. I mean, in ye olden days of 5k or 7.5k OCI's, it was also the right time to do a tire rotation. Often other service could be done (air filters, belts, whatever). At what point will they figure out how to code in routine service and "fudge" it so that it so that the oil change lines up with the next service call?
Maybe they do that already, maybe it's already done on the higher end stuff. And of course, any good service manage will try to sell service ahead of time. I just know that I'd find it annoying to "have" to go in at 7,500 for just a tire rotation, then have to go in again at 9k because the oil light went on (assuming I was a typical consumer and did zero work myself).
Maybe they do that already, maybe it's already done on the higher end stuff. And of course, any good service manage will try to sell service ahead of time. I just know that I'd find it annoying to "have" to go in at 7,500 for just a tire rotation, then have to go in again at 9k because the oil light went on (assuming I was a typical consumer and did zero work myself).
Always remember and never forget
All of these "monitors" do not take any direct sample from the oil and all of these equations are based on lab numbers measured against a specific oil mixture ( which may even be hypothetical) against a set scale or operational requirements.
They also do not account for variables such as wear, contamination, extreme usage or anything else.
Just always know that's how much they are worth and if your individual vehicle falls outside of the criteria then whatever reading you may get is not directly applicable to your situation.
All of these "monitors" do not take any direct sample from the oil and all of these equations are based on lab numbers measured against a specific oil mixture ( which may even be hypothetical) against a set scale or operational requirements.
They also do not account for variables such as wear, contamination, extreme usage or anything else.
Just always know that's how much they are worth and if your individual vehicle falls outside of the criteria then whatever reading you may get is not directly applicable to your situation.
They don't differentiate between idle RPM and 5000+ RPM ?
I've plotted the oil life in my wife's Fusion and while I've never went 10k miles on oil, it always trends towards ~12 months no matter the mileage. This is why some people see the % drop non-linearly if they watch it often enough. They adjust for "time" just as much (as GM says).
One of the lead engineers on this was on BITOG for a short time in the board's early days. Very knowledgeable but had a short fuse, got in a fight with some Amsoil people and stomped off. Pre DEXOS but his matra was oil is oil IIRC. When I went from an Encore to my Soul I missed the OLM. Changed at 20 percent. But now I just divide by five.
It can be done but that's IP and specific to the individual program
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The Fusion OLM was at 1% when the oil reached 10k (M1 AP) in 9 months.
The Tahoe has the 7500 mile limit … which I don’t mind being a GDI engine
Does the OLM assume a worst case scenario such as the cheapest (production wise) conventional oil or is it designed around the OEM fill?
In the early days of the OLM, say 1999 to at least 2004 there was no "one year limit" and the OLM ran to at least 12,000 miles. I know because I was discussing this with that GM (Northstar) Engineer mentioned above. I also ran my 2004 Chevy truck to 12500 going by the OLM, submitted a sample to Blackstone, and posted it on this board. The oil was just fine and said I had a bit more miles left on it, but not much. I imagine that engines were a bit easier on the oil back then since even the '99 Caddy (Northstar STS) didn't call for synthetic at that time.
As far as coordinating the OLM with other required service, Forget it. This is an oil monitor, not a tire monitor or anything else.
Now, for the Mercedes "OLM" not even close to GM's version. Appears to me to strictly be a time counter. This is evidenced by when I changed my oil on the E300 (4 cyl Turbo). Right after I told it which spec oil I used (yes, it asks!) putting in 229.6, it popped up a message saying "next service due in 365 days". Then they break that down into "Service A" and "Service B", so some things get checked on a biannual basis, others annually.
This actually gets you a bit closer to a "service monitor" since tire rotations and such can be done annually.
Close as I can figure, mercedes service is like this:
Service "A" = expensive
Service "B" = REALLY Expensive.
As far as coordinating the OLM with other required service, Forget it. This is an oil monitor, not a tire monitor or anything else.
Now, for the Mercedes "OLM" not even close to GM's version. Appears to me to strictly be a time counter. This is evidenced by when I changed my oil on the E300 (4 cyl Turbo). Right after I told it which spec oil I used (yes, it asks!) putting in 229.6, it popped up a message saying "next service due in 365 days". Then they break that down into "Service A" and "Service B", so some things get checked on a biannual basis, others annually.
This actually gets you a bit closer to a "service monitor" since tire rotations and such can be done annually.
Close as I can figure, mercedes service is like this:
Service "A" = expensive
Service "B" = REALLY Expensive.
I would guess it is based on whatever meets min spec in the manual. If an oil was that exceeded that spec, it might be usable for longer. Maybe. Then again, just what is exceeded, and if that is the critical spec, is an unknown. Fuel dilution might be an example of not being able to exceed x miles / rev's / gallons of gasoline even with a better oil.
Just clicked on the link provided by the OP. This info is not put out by GM, and after reading it is rather incomplete.
Lots more detail is available out there.
Lots more detail is available out there.
When I asked on Mopar app this is what I was told. The system checks oil with electric single as this determines oil condition, rpm, start cycle, ethanol content, outside temp, engine temp, mileage of engine, load of engine as well as overall health of engine. What this tells me is since they can check condition of oil then Synthetic oil will cause light to come on later as it flows better. He called it flex which is based off Mercedes Benz system.
The remarks are fairly consistent from owners of LS engines after the redesign of the LS engine oil system in 2014, (except for the 6.0 engine). They said the OLM counts down to 0 at the 7,000 mile range whereas it usually counted down to the 10,000 mile range previously. I just use 5,000 miles now but coincidentally I got my 6.0 LS to 200,000 miles using a calculated average of 7,000 miles over the past 12 years.
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What makes you think they're not the same ?
If the vehicle specs conventional, the OLM will be based on that (for 'safety' reasons). If it specs synthetic, the OLM will be based on that. If a customer chooses to use synthetic, they just have an add'l safety buffer.
I believe Honda has a contingency plan for these scenarios so that customers don't have to return in 1000 miles for a tire rotation, etc, etc. Was just reading this in the past week or two.
What makes you think they're not the same ?
If the vehicle specs conventional, the OLM will be based on that (for 'safety' reasons). If it specs synthetic, the OLM will be based on that. If a customer chooses to use synthetic, they just have an add'l safety buffer.
I ask because my local GM dealer has ACDelco full synthetic 0w-20 in the shop and listed in their system as the "OEM fill" for a particular 2020 vehicle. The manual states to use a synthetic 0w-20, 5w-20, 0w-30, or 5w-30. However, the OEM has to know that 90% of people that buy a new car may flip through the manual only to figure out how to work the new radio, and then it gets tossed in the glove box never to be opened again. Some of those same people are cheap in that they'll want the <$30 conventional oil change at Jiffy Lube or change it themselves with the cheapest conventional they can find with no regards to what the manual states. The average consumer has no idea what an API rating even is, much less Dexos or other OEM cert. Would the OEM assume such a worst case scenario for the OLM despite what is recommended in the manual and used in OEM fill?
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