Oil change intervals

Doublebase · July 8, 2018

On 7/5/2018 at 1:11 AM, qwank said:

I change all my vehicles oil every 3K miles or 12 months, whichever comes first. I use Dexos 5w30 in the '17 Silverado and synthetic Super Tech in everything else except my plow truck, which gets whatever I find around the shop for free, Usually the oil in the 5 gallon buckets that the oil pumps drip into.

I see way too many sludged up engines come through the shop following the OLM. or people thinking hey can go 10K-15K on oil.

If I remember you're a tech, right? I think you mentioned that before. I'll tell you what I've noticed; every Tech I know changes their oil out at 3,000 miles. EVERY SINGLE ONE. I'm not in the field anymore, I teach automotive, so it's not like I'm talking to 100 different techs a day, but the 20 or so I know personally change their oil at 3,000 miles using synthetic. I was the only one that believed in extended changes, they all thought I was nuts. And what happens?? The rings on my Lexus wore out. So me, this oil nut...this forum reading, telling these guys they're wasting their money dumping synthetic oil at 3,000 miles...ends up wearing out his engine at 160,000 miles. Was it because I was going 7,000-9,000 on oil changes? I don't know, but it sure looks like it. I never beat on the car, it was all highway mileage, I took great care of it, always garaged...but I bought into believing it was a waste to change your oil at 3,000 miles. Honestly I still think 3,000 is too soon...that I can go 5,000, but anything above that gives me the creeps now.

Doublebase · July 8, 2018

On 7/4/2018 at 12:59 PM, MarcuM said:

I’d like to think so too

it’s only 10mins once you’ve got a setup together to run the tube down the dipstick and pump out 4-5quarts and then $25 or so for atf Fluid

I’ve only had my truck 16months and it had 300 miles on it now I’ve put 90k on it so I know it’s not gonna last another 5-6yrs till it’s paid off from the bank lol

i got to Get at least 300k outta it before I go upside down on another trade in lol

Wait a second...you put 90,000 miles on your truck in a year and four months?? Holy crap!

The most I've ever personally seen someone drive is 50,000 a year, and I thought that was nuts. You've got him beat. What are you doing to put that many miles on your truck?

And if youre dead set on going 15,000 miles on your oil changes, I'd definitely consider using the Amsoil. And I'd be changing that filter out at 7,000 miles.

You should start a thread on your truck - you drive the most of anyone on here - I know I would be interested in hearing how your truck holds up long term - I'm sure others would too. Start a thread, take some pictures...update it once in a while. Tell us how it's doing, etc. Saw a guy do that once on a Lexus forum that drove a lot (not as much as you), it was easily the best thread on that site.

Edited July 8, 2018 by Doublebase

KARNUT · July 8, 2018

I was in the heavy equipment field for 40 years. We are OEMs for a few know manufacturers. As soon as synthetics became available we used them. Our field equipment was able to double the drain intervals on synthetics. The road gas and diesels went to once a year, some to 25k miles. Yes we did the testing, never lost an engine. Even car manufacturers are going extended. These are manufacturers that are known for 200K plus miles. Can’t imagine that they would jeopardize their reputation and have people come to their dealers less often for extended drains, if it was causing early wear. The 3K miles drain, no one is recommending that anymore, especially with synthetics.

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qwank · July 8, 2018

2 hours ago, Doublebase said:

If I remember you're a tech, right? I think you mentioned that before. I'll tell you what I've noticed; every Tech I know changes their oil out at 3,000 miles. EVERY SINGLE ONE. I'm not in the field anymore, I teach automotive, so it's not like I'm talking to 100 different techs a day, but the 20 or so I know personally change their oil at 3,000 miles using synthetic. I was the only one that believed in extended changes, they all thought I was nuts. And what happens?? The rings on my Lexus wore out. So me, this oil nut...this forum reading, telling these guys they're wasting their money dumping synthetic oil at 3,000 miles...ends up wearing out his engine at 160,000 miles. Was it because I was going 7,000-9,000 on oil changes? I don't know, but it sure looks like it. I never beat on the car, it was all highway mileage, I took great care of it, always garaged...but I bought into believing it was a waste to change your oil at 3,000 miles. Honestly I still think 3,000 is too soon...that I can go 5,000, but anything above that gives me the creeps now.

You are correct, I am a tech.

You'll be ok changing it at 5,000 miles on synthetic, no problems there. I write the stickers out at work for 5K, because we aren't allowed to write 3K unless it's a 2010 or older and takes conventional oil, but some techs still do it anyways.

That stinks about your Lexus, those cars usually run forever without problems.

Eddie 70 · July 8, 2018

I change my engine oil and filter every 5k miles. It's easy to keep up with and I feel comfortable doing it this way. I also, change 4 quarts of transmission fluid every 15k by pulling it out the dipstick tube. I changed the trans filter at 65k and have been doing the trans fluid every 15 since. It's easy maintenance and only takes a few minutes to do. I prefer preventative over corrective maintenance.

Cowpie · July 8, 2018

I generally concur with what techs think, but not always. Many of them are no more up to speed on things than their non tech counterparts, depending on what is being discussed. Coolant is one area where I find techs are woefully not up to date. I have had to have techs replace coolant because they put in the wrong formulation. And that correction was required per both the shop and the OEM. But their argument is "coolant is coolant". Had a Cummins shop in Des Moines have to replace the coolant after filling with the wrong stuff. A tech in a Cummins shop should know better, right? And oils come in a close second along with oil change intervals. Like everyone else, they generally base it on "feeling" and the way daddy did it and hardly ever on real testing and evidence. I have no problem if someone wants to change their oil every other week. Not my money. But to rely on what a tech says or does probably should be taken with a grain of salt.

The same techs would think I am bonkers for taking my commercial vehicles 50% longer than the OEM recommendation for oil changes. But I have stacks of used oil samples showing I could go even longer. A Detroit 60 12.7L I have now has 856,000 miles on the engine. Original injectors, turbo, fuel pump, etc. And it still uses less oil than most of the GM pickups on this forum. 2 qt or less in 22,000 mile oil changes. And it gets a 10w30 HDEO syn blend. OEM says oil should be changed in 15000 miles / 300 hrs. It gets changed at 22,500 miles / 450 hrs. 50% longer.

Many techs don't realize that for some of the add pack components to reach their full effectiveness, modern oils in modern engines should be taken longer than 3000 miles. There is plenty of evidence for this over at the BITOG website where there are many tribologists and lubrication engineers to explain it to anyone.

Edited July 8, 2018 by Cowpie

Supreme Pizza · July 8, 2018

How does the system work?

I'm sure most of you already know this, but for those of you that don't :

The GM Oil Life Monitor System is not a mileage counter or any kind of "oil sensor". It is actually a computer based software algorithm that determines when to change oil based on engine operating conditions. The computer program has no idea what brand, quality, or weight of oil you are using, and there is no actual oil condition sensor of any kind. You could replace your engine oil with grape juice, and it would not change the computers oil life estimates at all.

If there was some sort of actual oil integrity sensor, I would feel more comfortable using that system.

Edited July 8, 2018 by starman8tdc

swathdiver · July 8, 2018

The oil life monitor uses engine revolutions and temperature as its main calculations. It also uses time (one year limit) and for 2013+ mileage; automatically limiting oil change interval to 7,500 miles.

Supreme Pizza · July 8, 2018

19 minutes ago, swathdiver said:

The oil life monitor uses engine revolutions and temperature as its main calculations. It also uses time (one year limit) and for 2013+ mileage; automatically limiting oil change interval to 7,500 miles.

Limited to 7,500 miles? I wonder if that was a precautionary measure or if it was a necessity to reduce warranty claims.

swathdiver · July 8, 2018

39 minutes ago, starman8tdc said:

Limited to 7,500 miles? I wonder if that was a precautionary measure or if it was a necessity to reduce warranty claims.

Probably both. The OLM took for granted that people were using approved oil. Conventional oil is dead by 5,000 miles so by 7,500 miles it's making a mess inside. I run Mobil One and change it around 5K miles, the motor runs better even then. In other cars I've run Mobil One to over 20K miles and those motors ran fine but they too liked clean oil and ran better on it and got better gas mileage with clean oil.

Cowpie · July 8, 2018

Well, the OLM algorithms assume the oil meets the minimum GM standard. I know it has nothing to do with time on the oil, since I changed my oil yesterday and it was 13 months from the last change with about 4100 miles on the oil and 45% left on the OLM. Even using E85 for most of the last year didn’t really affect OLM.

Supreme Pizza · July 8, 2018

I enjoy changing my oil. I like working on mechanical things, and I love doing preventative maintenance. I find it to be entertaining. I would change the synthetic oil every 1,000 miles if it would not be ridiculous to do so.

Edited July 14, 2018 by txab

ChristopherDB · July 9, 2018

I wonder what the specs behind the software algorithm on the OLM consists of. I drive pretty hard, and in a hot climate. 6000 miles today and 23% life left. I was certain I was going to be due for my first oil change at 6k but I'm apparently on track for an 8k mile interval.

When I had a BMW it was supposed to have service at every 15k miles (funny how when they start including 5 year maintenance with the car it suddenly only needs oil every 15k) but I was always due for a change a couple thousand earlier due to my driving style and the computer calculating accordingly.

Supreme Pizza · July 9, 2018

Car manufacturers are in the business of making money. They spend hundreds of millions of dollars paying "think tanks" to figure out how to make them even more money. The end product is of no concern. If they were allowed to manufacture money printing machines, they would immediately stop production, service, and support for all of the automotive lines. Its all about the money. As it should be. Its not a charity. Sad but true.

swathdiver · July 9, 2018

48 minutes ago, ChristopherDB said:

I wonder what the specs behind the software algorithm on the OLM consists of. I drive pretty hard, and in a hot climate. 6000 miles today and 23% life left. I was certain I was going to be due for my first oil change at 6k but I'm apparently on track for an 8k mile interval.

See my earlier post on the subject. Even if your OLM said you had 15% and were at 7500 miles, it's supposed to be the limit nowadays. If yours does go past 7500 without calling for an oil change, please let us know.