lot of new cars have "oil monitors" extending your change intervals.

What exactly are they monitoring?
just back pressure across filter? viscosity? ???????

Do we trust them?

 

From my understanding the sophistication of the oil monitors on vehicles varies from manufacturer to manufacturer. I believe Ford uses somewhat of a dumbed down setup that is not what it could be.

 

As has been said there are a number of different systems & ways that oil life monitoring is being done & how well it'll work is dependent on how robust the system is designed to handle all of the pertinent variables & how well controlled the base line is.

For instance on systems that use algorithms to calculate when the oil is spent, rely on us at least using the specified oil & oil filter & input from the vehicles various sensors not being corrupt, to calculate from the drive cycle history, its best guess on when the oils ad pack is spent & turn the olm light on to say it needs to be changed.

Other systems measure the oils conductivity to make their best guess.

UOA is probably the most accurate, but then if our drive cycle changes over the next OCI, things change again, all a vicious circle.

SO, the oil life monitor is probably the next best thing, as most folks can't stand a lit warning light on the dash & will take the vehicle in for service to turn it off, so its served its purpose.

I do mostly short trip urban type driving & change my oil & filter every 6 months, so extending that out to say once a year, wouldn't save me much money, but to folks that ignore their vehicles service, or those that want to squeeze every last bit of life out of their oil, will likely approve of an olm system & if it cuts down on warranty repair, the manufacturers will like it too, as it'll make their regular warranty & especially their extended warranty gravy train even more profitable & as we've paid for the system that allows that when we bought the vehicle, the manufacturer isn't out of anything!!!!! A win/win for the manufacturer!!!!

 

Honestly as much as I do not like GM their OLM is very well done and it works great! It has proven to be reliable with lots of UOA's and most have even been able to get the OLM to go to -15% with oil life left. Now as far as GM's DEXEOS is concerned I think that is a sham!

 

Here is a link to a good multi page discussion on bobistheoilguy about olm's. A post on page two from a guy who claims to have worked on it, goes into some detail about how GM's algorithm works. It's set up for each engine & seems to have a 2:1 safty factor built in for OCI procrastinators.
How Chevy Corvette Oil Life Monitor Works - Bob Is The Oil Guy

Folks checking up on it with follow up UOA's have found it still has a comfortable safety factor built in, so if we use an oil & filter that is licensed to meet or exceed the manufacturers specifications, we should be good to go.

Some manufacturers require yearly OCI's, no matter what the olm says!!!!

Here is a link to info on Fords system, which sounds like it follows the GM model. http://owner.ford.com/servlet/Conten...=1239636411265

 

Toyota uses a "fake" oil monitor that just goes off every 5000 miles. Ive had BMW and Honda vehicles with a real system that uses various inputs, temperature being the most important IMO. UOA's have verified that there is a comfortable safety margin using the system.

 

hmmm
has anybody run the monitor on dinosaur oil, and then filled with a syn like mobil1 . and compared.

I know I used mobil1 in my 460 and change every 10k (filter at 5) I had it upto 250k when I gave it away (1 quart every 10k, and half of that probably went with the filter,

It physically didnt live to long with soninlaw driving it

 

09-10 F150s use the same fake monitor; 6 months or 7500 miles which ever comes first.

 

The system is calibrated for the factory fill recommended oil type. For example, older BMW's came with 15W-40 dino as factory fill, and the monitor system was calibrated for a maximum of 10,000 miles. Later cars came with BMW Long Life full synthetic (not generic API full syn) and 15,000 miles was the max. I usually ran 15W-40 Chevron Delo 400 but tried 10W-40 Castrol Syntec once. The system cant recalibrate itself for the Syntec.

Im not aware of which, if any, production cars sold in the US have the Delphi sensor that directly measures dielectric constant of the oil, presumably to detect level of contamination.

 

Hmm
impala just passing 3000 with 37% remaining. Im gonna put m1 in it and see.
Maybe I'll remember to back here in about 6 months and report

 

Yea right , monitors my oil.
It went off at 7000 miles "oil life zero
I pressed the reset button, I'm going to take it all the way to 10k, and now after an additional 1700 miles, it claims I have 97% oil life left.

I guess its just another gimmick to make me feel good about my payments

 

It doesnt monitor the oil itself, but engine operating condition. So, you told it that you changed the oil 1700 miles ago and it approximates 97% left. Tell me when it goes to zero again. Honda only reports 10% intervals until it reaches 15% left, at which time a little wrench symbol lights up. Mine is calibrated for dino and typically hits 15% at about 7000 miles.

 

Hmmm
dont remember if it said zero finally, may have been closer to change it now

 

BUMP:
New link to Fords input on how its IOLM works. Its a software algorithm based system, rather than a direct electrical oil quality measuring system. Guess it would depend on the Owner using a lube that says it meets or exceeds Fords specified motor oil specifications. Use a lesser quality oil & who knows how accurate its calculations may be!!!!
http://www.lombardfordwarrantys.com/...ence-Guide.pdf

 

At the end of the day, it's still a guess at best. Nothing is really "checking" your oil. The car's computer is using a very sophisticated algorithm to guess when you should change your oil. The car's computer really does not know what kind of oil you have in the engine, or what the condition of that oil is. I like that it's a very conservative algorithm. My new car alerted for oil change at 8,500 miles and 16,000 miles.