Current thoughts on GM OLM?

[UncleDave]

went by my 2002 silverado's OLM from 60k to 233K with zero issues. im going to shoot for 8k on HPL PCEO 5w-40.

So then you are moving off the OLM to a fixed mileage?

The GM OLM doest touch the oil, but assumes degradation and computes mileage remaining based on your habits and inputs against a given an API standard and specified grade.

It has no idea if you put in better or worse oil.

 

[BrendanC]

So then you are moving off the OLM to a fixed mileage?

The GM OLM doest touch the oil, but assumes degradation and computes mileage remaining based on your habits and inputs with the degradation curve tested against a given an API standard and specified grade.

It has no idea if you put in better or worse oil.

yes moving to a fixed mileage. will just reset the OLM whenever it comes up.

 

[CKN]

How many threads on this subject............................?

More than 10plus pages.....

 

[Jpc1623]

I have ‘20 Equinox w/ 1.5T, I’ve used PPPP, Royal Purple and Valvoline EP all in 0w20 flavor. I worked my way down the OLM from 24-18% had the oil tested by BS each time and each time they came back 8k miles or 5% left on OLM. Do I trust and like the OLM, yes will I go down to 5% only with boutique oil. I think 15-20% is reasonable considering how UOA came back.

 

[nickaluch]

I don't trust the OLM on the G6 beater since new but all my other GM vehicles I follow it no issues.

 

[MalibuRam65]

I do 5000 miles in everything else. Everything I own is GM with an OLM. I do not follow that thing. A standard oil analysis is 35 to 40 dollars plus shipping. So you do one a year. I do two oil changes a year on everything. It is about a wash.
Malibu oil change is about 45 bucks. Just change your oil, that is unless you have a certain problem you are looking for. Seems simple to me, then you know that oil and filter are good.
Oil change in the Buick is less than 40 dollars. Truck and Caprice is close to 70 dollars. The Trans Am is about the same as the Malibu.

Are you using Mobil 1 in all your vehicles?

 

[Malo83]

Never use it, just reset after my 5K oil changes.

 

[ls1mike]

Are you using Mobil 1 in all your vehicles?

Yes, except for the Buick and the Duramax.

 

[Ayrton]

My 08 Saab has this GM monitor. I don't really use it, I do reset it when I change the oil.

If I remember correctly, it goes off between 9000-9500 miles pretty consistently, closer to 9500.

 

[Falcon_LS]

Lake Speed Jr. has spoken quite highly of the GM OLM. Personally, I use it in my GM application but with a twist; when oil life hits 50%, I drain and refill the sump with fresh oil and replace the air filter. When oil life gets down to 1%, I change the oil, oil filter and the air filter. It usually hits 50% at around the 7,500 km (~4,690 mile) mark.

The only reason I do it this way with a drain and refill halfway in between is because no matter what air filter I use, no matter how well or tight the air filter is sealed, dust particles are extremely fine in this part of the world and some of it will still make it through and come up as silicon in UOAs. Running it all the way down to 1% has yielded decent results, minus the silicon. This is not something an algorithm will account for and this method has served me well enough that it is no longer a concern.

 

[SaberOne]

My OCD supersedes my OLM and is far more reliable.

 

[Patman]

Lake Speed Jr. has spoken quite highly of the GM OLM. Personally, I use it in my GM application but with a twist; when oil life hits 50%, I drain and refill the sump with fresh oil and replace the air filter. When oil life gets down to 1%, I change the oil, oil filter and the air filter. It usually hits 50% at around the 7,500 km (~4,690 mile) mark.

The only reason I do it this way with a drain and refill halfway in between is because no matter what air filter I use, no matter how well or tight the air filter is sealed, dust particles are extremely fine in this part of the world and some of it will still make it through and come up as silicon in UOAs. Running it all the way down to 1% has yielded decent results, minus the silicon. This is not something an algorithm will account for and this method has served me well enough that it is no longer a concern.

You’re changing your air filter too often. It doesn’t need to be changed every 7500km.

 

[Falcon_LS]

You’re changing your air filter too often. It doesn’t need to be changed every 7500km.

We may have to agree to disagree on that one.

Air filter after 2,160 miles in service

 

[Patman]

We may have to agree to disagree on that one.

Air filter after 2,160 miles in service

My bad, I didn’t realize where you lived! That’s a whole different scenario than what most of us over here will see. I have gone 70,000 km on the same air filter and it still looked clean.

 

[Snagglefoot]

There was a poll on the GM Gen IV and Gen V LS V-8’s. It seemed the Gen IV OCI was coming in at 10,000 miles but the Gen V ( which came out around 2014) was recommending 7,000 miles. That was good enough for me. I just went with 5,000 miles and I don’t lose sleep if it goes to 7,000 miles.

 

[SaberOne]

We may have to agree to disagree on that one.

Air filter after 2,160 miles in service

Given your location, I would have to agree with you on that.

 

[Falcon_LS]

My bad, I didn’t realize where you lived! That’s a whole different scenario than what most of us over here will see. I have gone 70,000 km on the same air filter and it still looked clean.

I can only wish I could go that long on an air filter here! Back in CA or FL, that may be easier to do; but out here, there's just no way.

The Fram Tough Guards with that light mist of oil on them actually perform really well over here though.

 

[silversport]

7500 miles or 1 year is the current (and for many years) OLM parameters with GM...if your older GM OLM is higher there is an update that can be performed at a dealership...

my 2005 GMC Yukon Denali 6.0 V8 goes to the single digits percentage wise in about 8 months or 4K miles (4167 miles) but the recommended oil is 5W-30 Dyno oil but has been replaced with full synthetic 5W-30...I suspect it could go longer but I will stick to the 4K or so oil changes and use the OLM as I find them reliable enough based on their design and my comfort zone

Bill

 

[IndyFan]

It absolutely does! Which is why I don’t understand why a lot of Corvette owners still ignore the OLM and do their oil changes every 3k. And it also is crazy that a lot of them won’t do their own changes. Instead of spending $200-300 at the dealer they could be doing it themselves for $60-70.

I do it myself and did my first one when I bought the car last June (M1 EP 5w30) and just did the second one at just over 5k (M1 0w40). I like the 5k OCI and won't go more than 1 year. I think this year may see more than 5k, but there will be a great deal of highway mileage, so I will probably still do it once a year, depending on the OLM and total mileage.

I know a bunch of Vette owners and most do it once a year with only 1k to 3k miles on them. But also, some of them run their cars really hard, including track time. If I took mine to the track, I'd probably do 3k.

GM at one point, IIRC, recommended a heavier oil (15w50?) if you take your Vette to the track. I wonder how much the OLM would factor hard running? I'd be inclined to think it would adjust accordingly.

As for me, my hard driving is in short bursts. Never anything like being on the track with sustained hard running for multiple laps. So I drive mine quite a bit, sometimes hard, but never track-like abuse and I don't do burnout starts. Even when driving hard, I am smooth. So I think once a year OCI will work out beautifully for my LS2 and it should last me the rest of my life, at the rate the miles are coming.

 

[twX]

GM at one point, IIRC, recommended a heavier oil (15w50?) if you take your Vette to the track. I wonder how much the OLM would factor hard running? I'd be inclined to think it would adjust accordingly.

The GM systems apply a derating/penalty factor for oil temperature above 130°C, and apply another derating based on the expected rate of oil contamination, which increases with engine load and rpm, and with other factors that increase fuel dilution. The total derating per mile will also increase with engine revolutions per mile, and this might be around 3 times higher than average when driving on the track.

In worst case conditions, the total oil life derating per mile in track driving could be up to a factor of 3x3x3=27 compared to ideal driving conditions.

With oil temperatures <130°C, the total derating per mile would only be in the range of 3 to 9, which wouldn't be much different than the derating in normal driving during engine warm up. If ideal conditions allowed for a 15k mile OCI, pure track driving might allow for an OCI in the range of 1.6k to 5k miles.

GM Oil Life Monitor Deratings/Penalty Factors, 2009: