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08 GMC, LMM. how reliable is the "% of oil life remaining" screen shown on the DIC? I am nearing my second oil change and the mileage on my truck is far less than the first oil change. Hope this makes sense.
Comments please!
 

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I think that % is set up for 7500 miles so i think that it bases off that number. I never use that and dont know many who do. I change every 5k, or if the oil seems darker or dirtier than should be.
 

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According to GM if you fallow the DIC your free and clear. As long as you take to the dealer to get it changed. I wondered the same thing when i got my LMM. I had a free oil change for buyin the truck (150 bucks for 50,000 what a deal!) so I used that at 3000mi and also had them change the fuel filter, both tranny filters and all the diffs. Reset all the life meters and drove it. Just rolled over 14000mi and the DIC went to 0 for oil and 51 for fuel. Took it in and had it switched over to 5W40 Rotella T full syn. asked the service writer about having a little over 10000mi on my fuel filter and still only at 50% and he said its fine and to follow the DIC. i said i will call you if it leaves me stranded.

Hope that made sense to you and answered your question.
 

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Thats the one thing I dont agree with the DIC for. I do mine at every 5000 miles no matter what the DIC says.

Ive always been told that changing your oil at the correct intervals is the best insurace you can buy. Mileage is what I go by! :cool:
 

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I have just over 10,000 on my LBZ and have changed the oil twice. However, the DIC has randomly reset the hours more than once (although the odometer seems OK) so I have settled on every 5,000 miles with fuel, transmission and oil filters at factory recoomended intervals. I don't trust the DIC

I say "DIC" but mine is a pretty stripped down truck. All I get is "Change oil soon" in the odometer window.
 

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08 GMC, LMM. how reliable is the "% of oil life remaining" screen shown on the DIC? I am nearing my second oil change and the mileage on my truck is far less than the first oil change. Hope this makes sense.
Comments please!
Thanks to everyone for their replies
 

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I was told by the dealer that I was perfectly safe going by the DIC. I just had mine changed after about 9800mi when the DIC got to 0%. They claim that several factors go into the percentage, not just mileage; engine load, fuel consumption, engine hours, miles driven, etc.
 

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and right there is the reason why i dont follow the dic. im sorry but i 85000 $ invested in this truck,and im not going to listen to something that was put in affect because of the green cry babys .
 

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08 GMC, LMM. how reliable is the "% of oil life remaining" screen shown on the DIC? I am nearing my second oil change and the mileage on my truck is far less than the first oil change. Hope this makes sense.
Comments please!
I (and you should, IMO :tease) treat the DIC as a suggestion as to where the extreme level is. It’s a good thing they added, as it varies with your usage, It gives the owner a base point to work from, depending on their use and abuse.

I use the ‘B’ trip meter to keep up with the Oil change intervals and compare that to the DIC’s version of what percentage is left. I pull/haul beyond GM’s suggested limits on a daily basis in at times, tough conditions. My changes are in the 5k area with the DIC reporting in the 40-percentile area, along with the Allison spin-on.

$9.85 here: Diesel Filters by Application - FleetFilter Online Store

Fuel filters at around 50% on the DIC, which is around 6-7k miles, unless performance changes, then sooner. Fluids and filters cost for me averages $66 every 5k miles or so, not bad I think. :D
 

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So, got a new truck and after driving it for about 2,800 miles, oil life DIC was saying to have it serviced. Went in to the dealer, they couldn't figure out why that was occurring, they changed oil and reset DIC back to 100% oil life. After going another 1,700 miles, oil life showed 44% left before changing it again. Doesn't make any sense! I do get the idea of every 5,000 and based on use, driving, towing, hauling, etc... but I barely do any of any of these things, just normal driving, so curious as to if anyone had nay feedback, similar experience or any ideas what's happening... Thanks!
 

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My DIC has always been in the 10-20% range with OCI around 8k miles. Minimal towing (maybe a bumper trailer with total pull weight of <2k #

This last oil change: 7% at a 2k miles. 300 to 400 miles of those were towing heaving (~14k #). The only difference is that I tuned it and towed heavy. However, the heavy tow only accounted for 15-20% of my total mileage.

I sent off the oil for analysis yesterday. If I remember, i'll post the results on here even though I have a decent feeling the results will be "why did you change it?".
 

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So, got a new truck and after driving it for about 2,800 miles, oil life DIC was saying to have it serviced. Went in to the dealer, they couldn't figure out why that was occurring, they changed oil and reset DIC back to 100% oil life. After going another 1,700 miles, oil life showed 44% left before changing it again. Doesn't make any sense! I do get the idea of every 5,000 and based on use, driving, towing, hauling, etc... but I barely do any of any of these things, just normal driving, so curious as to if anyone had nay feedback, similar experience or any ideas what's happening... Thanks!

What year is yours? Somewhere on here there is a post saying the DIC on the '19s was reading fast and GM was looking at the problem. Don't know why the algorithm for the '19 would be any different than the '17 and '18.
 

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For me 6 months comes WELL before 40% oil life on the DIC. SO I don't know what happens, does the truck explode when it gets to 0% ????
LoL
 

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My $.02,... everyone's truck is different. Mine gets the oil changed one a year because its stored in the winter in a heated garage and during the summer it pulls a 45' 5th wheel. It might get 5k on it a year.
My other vehicles run AmsOil. They say their oil is good for 25k. At one point I ran the same oil for 20k and it took 4 years to get that mileage. I sent it in for analysis and it came back to run it for another 3k and then change it.
Currently in run them to 15k and change the filters at 7500. Even though the oil is still good at 15k I'd rather have some good life left in the oil vs running it to max. Oil and filters are cheap compared to a new engine. I do extended drains at 15k because I run good oil, have it occasionally analyzed, and more so it's a pain to change, yukon and a G6. The truck on the other hand gets it once a year due to the amount of time it sits during the winter.
Depending on the oil and filters you use, I'd run it for 5k, or 7500k, and have it analyzed. That will be the best way to determine how often you should change it.
 

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If you tow a lot maybe 5000 miles, more solo than towing maybe 7500 miles, if you don't drive much then at least once a year.
Your engine will be much happier and live much longer.
Unless you feel you have engine issues don't waist your money on analysis put it towards servicing.

There have been a few guys over the years reporting going 20k because the uneducated on engines people at the analysis place kept advising them to go another 5k then retest.
After 20k analysis the report was CHANGE YOUR OIL IMMEDIATLY you have lots of metal in that old oil.
This one guy had 4 analysis done on the same oil, ($$$ out the window) once every 5k miles for 20k miles. 'uhNo

I fell for that analysts crap years ago (last one 2007) after my last report when they sent me another persons truck lab results, now I save my money.
My solid opinion. :wink2:

Big companies do oil analysis on big rig engines, but they have much larger oil filters and a much larger oil capacity and usually can go more miles, checking at least once in between changes.

On the LMM I know the oil life is set in the tuning to go from 100% - 0% in 10k miles. Nothing to do with the engines computer being smart enough to calculate oil life on its own.
 

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Unless you feel you have engine issues don't waist your money on analysis put it towards servicing.
Hindsight is 20/20 and it aligns with DRC's advice.

Change the oil regularly and based on use of vehicle. Doing anything more and you're fighting a battle of too many variables to control to get the desired (read: longevity) result you are likely looking for.
 

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Big companies do oil analysis on big rig engines, but they have much larger oil filters and a much larger oil capacity and usually can go more miles, checking at least once in between changes.
extended OCIs means less downtime = savings.

They have a cost-justified reason for OAs.
 
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