GM Offers Oil Life Monitor Information

[ABN_CBT_ENGR]

I swore when I was a GM tech that I read information that the OLM took into account Time, Miles, Engine revolutions, Operating temp, cold starts, engine load, ect.... Granted Some of these play into oil life more than others.

I have always thought gm was ahead of the curve on OLMs.

Don't doubt that for a second nor do I doubt the GM OLM most likely considers all you listed but even a few more.

They might even be ahead of the pack too

Its not the manufacturer or even the concept, algorithm, or anything else- there is a hard ceiling of accuracy that will never be surpassed unless and until the technology goes beyond a non invasive no contact method of analysis.

Its no different than your doctor assessing your temperature over the phone by you describing the weather outside.

 

[Benzadmiral]

StackPath

Is that a 2017-2019 Buick LaCrosse as the illustration at the head of their story? A car they don't make any more, sadly.

ETA: Looks like it might be the Regal Sportback. Since Buick no longer offers, yanno, cars, the pic seems like an odd choice.

 

[JohnnyG]

do not and did not have any GM with an OLM but your statement i what I believed as well. My Forld OLM was IMHO behind the curve. GM was not exactly advanced compared to modern BMW and MB (not sure of Acura or Audi). For those of us who are locked into our vehicles, until we get an OLM that replicates an actual oil analysis it will always be a subpar tool. At the cost of modern vehicles you would think the algorithms would have come farther toward that end.

Actually, you have this a bit backwards. The GM OLM is much more advanced than the Mercedes system. The Mercedes system even in my 2018 just simply counts the days since the last reset. It will call for service every 365 days no matter how far or how hard you drive.
The GM system takes many factors into account, and subtracts adverse operating conditions from an "IDEAL" situation. The "ideal" in 1999 & 2000, the two which I am most familiar with was 12,000 miles. I understand that was shortened in later years and on different engines.
I don't know anything about BMW's system, or VAG, or Acura, but unless they licensed the patented GM OLM, I doubt that they are much better than MB's.

 

[OVERKILL]

Actually, you have this a bit backwards. The GM OLM is much more advanced than the Mercedes system. The Mercedes system even in my 2018 just simply counts the days since the last reset. It will call for service every 365 days no matter how far or how hard you drive.
The GM system takes many factors into account, and subtracts adverse operating conditions from an "IDEAL" situation. The "ideal" in 1999 & 2000, the two which I am most familiar with was 12,000 miles. I understand that was shortened in later years and on different engines.
I don't know anything about BMW's system, or VAG, or Acura, but unless they licensed the patented GM OLM, I doubt that they are much better than MB's.

IIRC, the more recent BMW ones actually have a sensor in the oil that measures characteristics.

 

[JohnnyG]

From BMW's website:

How BMW’s Condition Based Servicing (CBS) system works and what to expect​

BMW’s Condition Based Servicing (CBS) system actively monitors engine and other vehicle components for wear. This system monitors the oil life, cabin air filter, brake pad wear, condition of the brake fluid, spark plugs, and, with diesel engines, the diesel particulate filter.

If the BMW model is equipped with the iDrive on-board computer system, the number of miles before a certain service is due will be located on the lower central section of the dashboard when the vehicle is turned on. On other models, the service information will be located on the instrument panel.

The CBS system tracks oil life through mileage, the amount of fuel consumption, and information about oil quality from a sensor located in the oil pan. Certain driving habits can affect the life of the oil, as well as driving conditions such as temperature and driving terrain. Lighter, more moderate driving conditions and temperature will require less frequent oil changes and maintenance, while more severe driving conditions will require more frequent oil changes and maintenance. It is unclear whether the CBS system takes into account these factors, so it is important to be aware of this and to check your oil periodically, especially for older vehicles with higher mileage. Read the table below to help you determine oil life for your specific vehicle:

• Note: Engine oil life is dependent not only on the factors listed above, but also on your specific vehicle model, year, and what type of oil is recommended. Check the owner’s manual for more information about what oil is recommended for your vehicle, and don’t hesitate to get in touch with one of our experienced professionals for advice.

 

[CKN]

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.

They do take in to account extreme use via engine rpm's. They can take in to account every driving condition EXCEPT dusty conditions. A vehicle will last a long time using the OLM and the proper oil spec-that's the bottom line.

 

[ABN_CBT_ENGR]

They can take in to account every driving condition EXCEPT dusty conditions.

They CANNOT take any "driving condition" into anything. They can take RPM readings and other pressure/flow readings against a timer and calculate. ( a car doesn't have that many sensors so that tells you the inputs available).

They also cannot take into account subtle changes such as leaks, effects of wear, contamination or anything else.

Like I said, an INDIRECT measurement based on laboratory parameters calculated by an equation.

A vehicle will last a long time using the OLM and the proper oil spec-that's the bottom line.

A vehicle ( properly maintained and all that) with the proper spec oil REGARDLESS of what the OLM says ( or doesn't) will likely last a long time.

 

[CKN]

They CANNOT take any "driving condition" into anything. They can take RPM readings and other pressure/flow readings against a timer and calculate. ( a car doesn't have that many sensors so that tells you the inputs available).

They also cannot take into account subtle changes such as leaks, effects of wear, contamination or anything else.

Like I said, an INDIRECT measurement based on laboratory parameters calculated by an equation.


A vehicle ( properly maintained and all that) with the proper spec oil REGARDLESS of what the OLM says ( or doesn't) will likely last a long time.

The point being you can properly maintain your vehicle following the OLM. Most do not keep a vehicle long enough to worry about leaks, effects of wear, etc. That's only in the world of BITOG. And those on here are proving that point by buying cars with 100,000 miles (or more) and driving them for another 100,000 miles. Most are following the OLM on these vehicles that BITOgers are acquiring.

 

[ABN_CBT_ENGR]

The point being you can properly maintain your vehicle following the OLM.

I agree completely (in normal cases) and have never said otherwise.

My single point is only that no OLM is a DIRECT representation of the condition of a motor oil.

 

[OVERKILL]

From BMW's website:

Yup, that's what I was thinking of. It's pretty interesting to see how technical they've gotten with it.

 

[blingo]

A few simple automotive sensors are around for quite some time. https://bobistheoilguy.com/forums/threads/gm-offers-oil-life-monitor-information.331512/post-5516438

 

[JohnnyG]

Yup, that's what I was thinking of. It's pretty interesting to see how technical they've gotten with it.

In my opinion, and after reading exactly what the BMW system "tracks" it's not much more than a MILEAGE counter. Now, I realize that everyone will read that post and get something different out of it. There IS an oil "sensor" in the pan. Even THEY don't seem to know what it does. It may be a temperature sensor, or a level sensor, but they wouldn't go through the trouble of explaining different "USE CASES" if it were somehow able to sense the quality and life left in the oil.
This paragraph alone tells the tale:

The CBS system tracks oil life through mileage, the amount of fuel consumption, and information about oil quality from a sensor located in the oil pan. Certain driving habits can affect the life of the oil, as well as driving conditions such as temperature and driving terrain. Lighter, more moderate driving conditions and temperature will require less frequent oil changes and maintenance, while more severe driving conditions will require more frequent oil changes and maintenance. It is unclear whether the CBS system takes into account these factors, so it is important to be aware of this and to check your oil periodically, especially for older vehicles with higher mileage. Read the table below to help you determine oil life for your specific vehicle:

So they're hedging their bets on the oil life.
GM still has the best system, in my opinion, and using it will reduce environmental impact as well as impact on your wallet.

 

[OVERKILL]

In my opinion, and after reading exactly what the BMW system "tracks" it's not much more than a MILEAGE counter. Now, I realize that everyone will read that post and get something different out of it. There IS an oil "sensor" in the pan. Even THEY don't seem to know what it does. It may be a temperature sensor, or a level sensor, but they wouldn't go through the trouble of explaining different "USE CASES" if it were somehow able to sense the quality and life left in the oil.
This paragraph alone tells the tale:

So they're hedging their bets on the oil life.
GM still has the best system, in my opinion, and using it will reduce environmental impact as well as impact on your wallet.

That says it is from "Your Mechanic" and links to yourmechanic.com Which makes sense, as I wouldn't expect BMW to say they don't know what their own oil life monitor does.

That link was from here: https://www.yourmechanic.com/article/understanding-bmw-service-indicator-lights-by-brent-minderler

Here's something that reads a bit better:

http://www.bgdiagnostica.com/BMW/bmw_cbs_bulletin.pdf

BMW themselves are pretty vague on how the system operates other than indicating that it uses the operating conditions to modify the schedules.

This, if accurate, is a bit better of an explanation:

BMW Condition Based Service System

Some vehicle manufacturers estimate oil by using mathematical algorithms. The oil monitor keeps track of hours of engine operation, temperature, distance traveled and so on to estimate how much oil life is left. When a certain point is reached, the oil service reminder light comes on.

BMW uses an "adaptive" strategy to compute estimated oil life based on how much fuel the vehicle has consumed (which BMW says is more accurate than tracking the number of miles driven and hours of engine operation). The CBS system also considers input from an oil quality sensor in the bottom of the oil pan. The oil quality sensor measures the electrical conductivity of the oil. As the additives in the oil wear out, the resistance of the fluid changes.

The maximum service interval on late-model BMWs with this system is 25,000 km (15,500 miles, which the driver information display rounds up to read 16,000 miles). As the CBS system tracks fuel usage, it deducts mileage in 1,000-mile chunks from the remaining oil life. When there is an estimated 1,250 miles of oil life left, or if the oil quality sensor indicates a change is due sooner, the service reminder light comes on, and the oil status indicator changes color from green to yellow. Keep in mind that the 15,500-mile oil change interval is based on using BMW's High Performance 5W-30 synthetic oil, not ordinary oil. Also, most of these engines hold 7, 8 or 9 quarts of oil, depending on their crankcase capacity.

It is not clear whether BMW takes into consideration wear factors that accumulate with normal driving. A 15,500-mile oil change interval may be okay for a low-mileage engine with no piston ring or cylinder wear, but what about an engine with 100,000 or 150,000 miles on the odometer? Such long oil change intervals with a high-mileage engine that has more blowby and wear than a new engine may be asking for trouble.

 

[ABN_CBT_ENGR]

This, if accurate, is a bit better of an explanation:
BMW Condition Based Service System

One of the immediate problems I see is this conductivity sensor.

That's not very reliable in oil ( more so in hydraulics and turbines) and there's no true linear correlation between conductivity and an oils given state due to the numerous things ( some serious- some not) that can affect it.