Oil Life Monitor

[jagabom (Esquire)]

Once a year I travel 5000 highway miles. I change the oil just before I go. By the time I return the OLM is down to 60%. Around town it drop lots faster.

Jim

[Reidan]

Do you do your first oil change much earlier than the OLM indicates. I have typically done around a 1000 miles on my other trucks. Is it a good idea on newer engines?

[RyanbabZ71]

Do you do your first oil change much earlier than the OLM indicates. I have typically done around a 1000 miles on my other trucks. Is it a good idea on newer engines?

I have always done 500-1000 miles on the first oil change

 

 

Ryan

[Boardmember]

As stated above, the dealer cannot alter the limits of the Oil Life Monitor, that option does not exist for dealers.

 

Ok. My dealership is a credible, but small town outfit. Now that I have the opportunity (maybe that should be in quotation marks?) to visit again soon because of the recall, I will ask.

[toro1966]

I don't buy that it drops to zero after a year. I have a 2015 Sierra Denali with about 2700 miles on it. I need to change it now, but my OLM still says about 30 percent and I have never changed the oil. Bought it last Aug,

[RyanbabZ71]

I don't buy that it drops to zero after a year. I have a 2015 Sierra Denali with about 2700 miles on it. I need to change it now, but my OLM still says about 30 percent and I have never changed the oil. Bought it last Aug,

It doesn't, I do a yearly oil change on my car. Typically the OLM is in the 85-90% range.

 

 

Ryan

[Reidan]

Oil was in the ground for 65 million years. I doubt sitting in your engine block for a year is gonna degrade it that much that quickly.

[SouthernSilveradoGuy85]

Oil was in the ground for 65 million years. I doubt sitting in your engine block for a year is gonna degrade it that much that quickly.

 

I believe it's not the oil itself that comes out of the ground, it's the additives that companies add to it. I also believe that those additives is what breaks down in the oil which is why you change the oil in the first place, because it has broken down to the point that it no longer does what it's supposed to.

[FL335i]

Again guys, GM has a algorithm that monitors inputs such as engine temp, rpm, fuel consumed, etc. All that sensory input affects the % drop according to the algorithm. In 2008-2010 I think GM was pushing the envelope with the OCI baseline. I had a 2008 4cyl Pontiac G6 company car. Brand new off the lot. I drove it for 3yrs and 100k. It would go 10-12k miles IIRC if I went the entire life. I normally did OCI's around 6 or 7k around 40% left. Again, my father inlaws '12 4cyl Equinox used to take him about 10-12k and then the dealer did a recall/TSB re flash and now it will not take him past 7,500 miles. Use a quality oil filter (AC Delco, M1, Royal purple etc) and run the proper oil weight and spec. Reset the OLM and drive. GM has way more R&D on this than us guys... they've been doing the OLM since the early 90's. I run my truck down to about 15%-10%. 0w-20 Pennzoil Platinum which is Dexos 1 approved and full syn. I used to run the older metal cage AC oil filters while I could find them at Walmart, and since they went to the E-core I now run M1's. Move on in life.

Edited September 11, 2016 by FL335i

[Skiludd]

My 2018 Silverado has only 5435 miles on it. According to the monitor I have already had to change oil twice and it is now at 62%.  Why is it degrading just by sitting?  If oil degrades by sitting then oil sitting on the shelf is no longer useable. 

[Bikemobile]

On 9/9/2016 at 8:37 PM, Boardmember said:

NOTE: I had my oil changed this week and told the #2 advisor I wanted full synthetic. She said the dealership used a syn blend but I said for the $25 up charge I wanted to run full syn. She said ok then a few minutes later came into the waiting room and asked how many miles I wanted the OLM set to to indicate my change interval. Um, 7500. Ok. Done.

Maybe she asked for the little window sticker? 

[Ernessch]

I just bought a 2018 Silverado Dealership Demo with 3214 miles on it. I checked and the last oil change was at 2925 but 14 months ago. At my insistence the dealership changed the oil due to the length of time since the last one being so long. After 185 miles of 60% highway and 40% city driving my monitor reads 91%. At this rate it appears I'll get less than 2000 miles before my oil needs changed. Why has my oil life % dropped so fast in two weeks of driving? Does the % drop quicker right after an oil change? I checked and the monitor was reset. Thanks for any insight to this expensive issue. 

Edited July 8, 2020 by Ernessch
Misspelled word

[Salsa De Piña]

Mine tends to drop quickly for the first 10%, then slows down after that.  Doesn't seem to matter if I'm booting around town or on the highway.

[Grumpy Bear]

On 9/10/2016 at 8:30 AM, elcamino said:

 

Since 2010 all GM vehicles have been equipped with the oil life monitor (OLM) system

The monitor calculates the percent of oil life remaining, based on 3 pathways

 

The OLM starts its calculation for all pathways after the first 50 miles to account for marshalling and time before sale. Subsequently, calculations begin immediately after each reset.

 

Recommendation/Instructions

 

Oil Life Monitor Calculation Pathways:

1. Engine revolutions- Oil life starts with a fixed number of revolutions and will decrease with each revolution. Cold / hot coolant temp readings have multipliers that reduce engine revolutions pathway quicker depending on how far from the normal oil temperature the vehicle is operating.

Note: If engine coolant temp gets above 260F, engine overheat condition, the oil life will go to 0%.

2. Mileage from last reset – Starting with MY 2013, the OLM is capped at 7500 miles for all GM powertrains except the Volt. In perfect conditions a vehicle would reach 7500 miles from the last reset and the oil life left would be 0%.

3. Time- This pathway is a liner function, a fixed decrease in oil life for a given time after the oil life is reset. The oil life will drop to 0% after 1 year regardless of the amount of engine revolutions or how many miles since the reset.

Note: The Volt uses a 2 year timer instead of 1 year. It also uses the engine revolution counter. It does not use the mileage pathway to count down.

 

On 9/10/2016 at 9:34 PM, Reidan said:

Oil was in the ground for 65 million years. I doubt sitting in your engine block for a year is gonna degrade it that much that quickly.

Interesting that is.

 

I just noticed a difference between my trip meter mileage and the odometer mileage.  I suppose I should have caught it quicker but I got lazy and only used the trip for my calculations. Had I used both I would have noticed the odometer puts miles on faster than the trip. Not a few tenths either (per fuel stop). I made a marker in my log and will do a long term compare starting now. 

[Ernessch]

3 hours ago, Ernessch said:

I just bought a 2018 Silverado Dealership Demo with 3214 miles on it. I checked and the last oil change was at 2925 but 14 months ago. At my insistence the dealership changed the oil due to the length of time since the last one being so long. After 185 miles of 60% highway and 40% city driving my monitor reads 91%. At this rate it appears I'll get less than 2000 miles before my oil needs changed. Why has my oil life % dropped so fast in two weeks of driving? Does the % drop quicker right after an oil change? I checked and the monitor was reset. Thanks for any insight to this expensive issue.