Oil life indication?

[nickpohlaandp]

So here's a question. How does your oil life indication work? I mean, is there some sensor that analyzes the properties of your oil, monitoring the acidity and contaminant levels, or is it just a BS number that computes from a set value whenever you reset it?

 

[Kotta390]

So here's a question. How does your oil life indication work? I mean, is there some sensor that analyzes the properties of your oil, monitoring the acidity and contaminant levels, or is it just a BS number that computes from a set value whenever you reset it?

I too am intrigued. I change my full synthetic oil at 5000 miles and my OCI says I usually have 49-51% left every time.

 

[nickpohlaandp]

I've read that there's two ways manufacturers do it. One way is using an algorithm in the PCM that calculates the oil life based on many factors (idle time, drive time, temperature, load, etc.). It's a constantly changing formula built into the PCM that comes up with an average and displays it on your EVIC. The other way manufacturers do it is with actual gauges that actually measure resistance, viscosity, water content, etc. I'm curious to know which is used on our trucks.

I don't want to say this, but I'm betting ours is the algorithm method.

 

[Bobbo]

I believe it calculates it based on driving styles. Takes into account things like engine RPM, load, temperature, etc... So if you do more city driving, it will have you change the oil sooner than mostly highway driving.

Sent from my LG-H820 using Tapatalk

 

[Kotta390]

I've read that there's two ways manufacturers do it. One way is using an algorithm in the PCM that calculates the oil life based on many factors (idle time, drive time, temperature, load, etc.). It's a constantly changing formula built into the PCM that comes up with an average and displays it on your EVIC. The other way manufacturers do it is with actual gauges that actually measure resistance, viscosity, water content, etc. I'm curious to know which is used on our trucks.

I don't want to say this, but I'm betting ours is the algorithm method.

I can almost guarantee it. The algorithm theory is something I have been wondering if Chrysler used. Your second theory on the calculation is probably for more advanced vehicles out there like your Jag, Mercs, and BMWs or higher.

 

[nickpohlaandp]

I can almost guarantee it. The algorithm theory is something I have been wondering if Chrysler used. Your second theory on the calculation is probably for more advanced vehicles out there like your Jag, Mercs, and BMWs or higher.

Without knowing for sure, I'd bet $ that you're right. An algorithm like that would actually be pretty easy to write, and in mass production, easy equals less money, which equals more profit.

 

[develand]

I don't pay attention to it. I use it more for the miles since last change.

 

[Ram Man]

I too am intrigued. I change my full synthetic oil at 5000 miles and my OCI says I usually have 49-51% left every time.

I am at 4,950 miles on synthetic and I have 49% left... With that being said I will not be going 10,000 before I change the oil.

 

[nickpohlaandp]

I am at 4,950 miles on synthetic and I have 49% left... With that being said I will not be going 10,000 before I change the oil.

Oh, I agree. I change mine every 5K, but I was just curious if anyone knew for sure what method is used for the display.

 

[Danno]

From the owners manual

Oil Life Reset
Your vehicle is equipped with an engine oil change
indicator system. The “Oil Change Required” message
will flash in the DID display for approximately 10
seconds after a single chime has sounded, to indicate the
next scheduled oil change interval. The engine oil change
indicator system is duty cycle based, which means the
engine oil change interval may fluctuate, dependent
upon your personal driving style.

 

[sandawilliams]

From the owners manual

Oil Life Reset
Your vehicle is equipped with an engine oil change
indicator system. The “Oil Change Required” message
will flash in the DID display for approximately 10
seconds after a single chime has sounded, to indicate the
next scheduled oil change interval. The engine oil change
indicator system is duty cycle based, which means the
engine oil change interval may fluctuate, dependent
upon your personal driving style.

I have been to two different dealers since buying my 2014 new. They have both told me the same story- change the oil when the indicator says to. I researched online and found many more articles that agree. I wonder how reliable this is but it is costing the dealers money (less from oil changes) to tell people that. Neither of the dealers put the old style date and mileage stickers on the windshield anymore.

 

[MANual_puller]

I just ignore mine, I reset it when it annoys me. It seems to think I should go 7500ish miles on the oil. I use Mobil 1 but I still don't feel the need to go that far on oil.

 

[jag1886]

It's basically a timer, like the light on your refrigerator that tells you to change the filter. If you don't reset it at an oil change it doesn't know you changed the oil.

 

[socalledchad]

Mine has always seemed to be on par with 10k miles..if I drove 5k it says 50% left....even thought I pull 4 k 10% to 80% of the time and all types of driving styles...and winter summer changes...makes me believe it's just millage ...but it's said that there is more to it

 

[Hootbro]

I have heard both algorithm and mileage base opinions. I will say that with mine, you can count on a 1% tick loss every 80 miles not matter how I drive which is in line with my recommended 8K change interval on the 6.4.

 

[thediamondsaint]

Are you sure it's not just based on the miles? That seems to be the only number indicated in the dash menu for Oil Life. I'm on 49 miles since my last oil change.

 

[Danno]

Are you sure it's not just based on the miles? That seems to be the only number indicated in the dash menu for Oil Life. I'm on 49 miles since my last oil change.

Once again....

"The engine oil change
indicator system is duty cycle based, which means the
engine oil change interval may fluctuate, dependent
upon your personal driving style."

 

[Ram Man]

If you don't reset it at an oil change it doesn't know you changed the oil.

Exactly. If it was an algorithm with sensors and such and actively monitored the oil, then there would never be a need to reset it when it got low. Because if it looked at the oil, it would automatically go back up to 99% when you put fresh oil in. But we all know that is not the case...

Settled.

 

[BlakDak71]

Like everybody else has said, the PCM calculates it based off driving habits, ambient conditions, cold starts, idle time, etc.

No magic sensor to analyze oil properties. It's really just an idiot light and should be treated as such. 5000-6000 miles is safe with newer engines, provided you actively check your oil - especially with the Hemis tendency to suck oil through the PCV system.

 

[nickpohlaandp]

Like everybody else has said, the PCM calculates it based off driving habits, ambient conditions, cold starts, idle time, etc.

No magic sensor to analyze oil properties. It's really just an idiot light and should be treated as such. 5000-6000 miles is safe with newer engines, provided you actively check your oil - especially with the Hemis tendency to suck oil through the PCV system.

In 5000 miles my catch can was maybe 1/4 full, and that's being generous.