[396ssrat]

2019 Camaro LGX v6.
26 months old has 1510 miles. Had 2nd oil change 4 months ago and has been driven less than 200 miles since. Looked at the oil life monitor today and it's at 65%. How is this possible? It has the recommended Dexos 2 and was changed at the dealer. Yes, they did reset it when they changed it.
I don't think I'd change it in my older car until it had at least 3000 miles on it.

[ifound1dollar]

The oil life monitor in the gen 6 takes into account time since last oil change in addition to miles driven, engine rpm, etc. It's recommended that engine oil be changed at minimum once a year even if the car has been driven minimal miles, and the OLM takes that into account. It'll hit 0% after a full year even if the car hasn't been driven a single mile.



Since its been ~1/3 of a year since the last oil change, it makes sense that it there's ~1/3 less oil life remaining even with only a few hundred miles driven.

[2SS Capt]

Originally Posted by ifound1dollar

The oil life monitor in the gen 6 takes into account time since last oil change in addition to miles driven, engine rpm, etc. It's recommended that engine oil be changed at minimum once a year even if the car has been driven minimal miles, and the OLM takes that into account. It'll hit 0% after a full year even if the car hasn't been driven a single mile.



Since its been ~1/3 of a year since the last oil change, it makes sense that it there's ~1/3 less oil life remaining even with only a few hundred miles driven.

This...

Change the oil at least 1 time per year even if you only drive minimal miles...

[Camaro fanboy]

yearly or milage. even if you never drive it the whole year the car will say change the oil

[Number 3]

So to be clear you saw it read 100, drove 200 miles and now it shows 65?

This would be a lot of idling.

[Sweptwing]

Chronological + mileage! As Camaro Fanboy said, if you never put a mile on it, in 1 year it would require an oil change.

[avalonandl]

Originally Posted by Sweptwing

Chronological + mileage! As Camaro Fanboy said, if you never put a mile on it, in 1 year it would require an oil change.

My 2015 Duramax 3/4 ton did the same thing. Sit for 4 months and lose 30% of oil life.

[396ssrat]

Originally Posted by Number 3

So to be clear you saw it read 100, drove 200 miles and now it shows 65?

This would be a lot of idling.

Car has been parked.

[396ssrat]

So I guess the oil that sits on the shelf for a year should be discarded? NOT!!!!!!!!!!!
Modern engines are pretty well sealed from what I've seen. After all, we don't want those pesky fumes in the atmosphere.

[FarmerFran]

Originally Posted by 396ssrat

So I guess the oil that sits on the shelf for a year should be discarded? NOT!!!!!!!!!!!
Modern engines are pretty well sealed from what I've seen. After all, we don't want those pesky fumes in the atmosphere.

I am no expert and i am sure someone will chime in but other factors could be at play like presence of air and water and other contaminates causing it to break down in the engine vs. The original sealed container. I am pretty sure once you open oil it has a finite shelf life

[Gunkk]

The OLM will go to zero in one year even if the car is not driven. Time is very much part of the algorithm.

[UnknownJinX]

Originally Posted by FarmerFran

I am no expert and i am sure someone will chime in but other factors could be at play like presence of air and water and other contaminates causing it to break down in the engine vs. The original sealed container. I am pretty sure once you open oil it has a finite shelf life

Bingo.

Blow-by gas will definitely contaminate the oil once you put it in the car, not to mention the small amount of dirt, carbon and other things that can end up in the oil.

Not to mention, blow-by gas will eventually make the oil slightly more acidic, which isn't particularly great for metals.

[396ssrat]

Originally Posted by UnknownJinX

Bingo.

Blow-by gas will definitely contaminate the oil once you put it in the car, not to mention the small amount of dirt, carbon and other things that can end up in the oil.

Not to mention, blow-by gas will eventually make the oil slightly more acidic, which isn't particularly great for metals.

Blow by on a new completely sealed engine that is parked and not running. No different than oil in a sealed container. EPA goes to great lengths to prevent vapors.
In my mind it's just a way gm can sell oil changes and they use the warranty as leverage.

[Scottyz]

I personally have never felt that time is that big a deal. Years and years and some time of outside exposure…..yeah ok maybe a bit. GM likely does this to cover their arses a bit. I have owned numerous vehicles that have sat for sometimes as long as five years without really getting driven. Probably longer. My oil would look fine. Once I took them out of storage I would drive them awhile then change the oil that was years old.
I’ve been a licensed tech for over 25 years on heavy equipment and automotive.

Hell we have pulled machines out of our hole at work that sat for over ten years outside in the elements. Birds, raccoon, rats nests. We will get them running on the existing oil lots of times then crawl them out of the hole and then service them. Were the engines tip top? Likely not but ran fine. They weren’t big smoking messes.

Would I recommend doing this. No. But I personally think GM uses the time on the OLM for warranty purposes and it also gives dealers a chance to eyeball said car under warranty and if the vehicle is out of warranty then the dealer may have a chance to upsell some work.

Hell I’m looking at my Escalade right now and I just changed the oil out about 5 months ago. Before that it was almost 2 years if I remember correctly but the oil was still clean.

But I will say this……all my vehicles typically get their oil changed well before the mileage recommendation. So if it’s 5000kms I will typically do 3-4000.