What Oil and Oil Change Interval for Your K2?

Spurshot · March 21, 2015

I'm interested to hear what people are planning on doing for their oil and the change intervals on their new trucks? Filters too. Let's hear your reasons for your choices too.

I'm a fan of Mobil 1. I've used it in the past few trucks. One truck is at nearly 300,000 miles and runs like a top, the other is past 150,000 now. All of my past few trucks got Mobil 1 (of the OEM recommended viscosity) at the first recommended change interval. My K2 got it at 9000 miles (1st change per the on-board Oil Life Monitor). I'm using the OLM as the interval, which seems to be around the 9000 mile mark for my driving. I'm at the second interval now and will put in M1. I had been using Mobil M1 and K&N filters (Wix from my understanding), but I also bought the last 3 PF63 filters from my local Walmart along with their complete stock of M1 0w-20 Extended Life Oil (10 jugs of the 5 qt size for $26 on "rollback")

I'm just using a synthetic because of a test a friend that worked at Honda conducted some 20 years or more ago. The test proved M1 was superior in wear protection to a host of premium brand mineral oils (at that time). So, I started using Mobil 1 and never tried/changed brands. I haven't read anything that leads me to believe there's an advantage to switching brands and my past truck experiences have kept me on the oil change intervals per the OLM. That combination has kept the engines running perfectly for the durations I've owned them and still with their second owners today. What's not to like?

Here's what happens when you don't change your oil for 84K.

Silverado-Hareek · March 21, 2015

I plan to stick with a synthetic blend, regular AC Delco filters, and do my changes every 5,000 miles with a tire rotation at the same time. That way I can always time my oil changes with my tire rotations making maintenance easier to track and with a 5,000 change interval, there's no need to spend the money on full synthetic at that low mileage change rate. My side mechanic swears regular oil is better than full synthetic. Something about they don't test any engines with full synthetic at first, they always use regular because it shows them something.....I dunno it was a lot of mechanic technical stuff that I'm not well versed in. He was also saying full synthetic is so good at not breaking down that it can cause it to slip by seals and stuff. He recommends the synthetic blend as the best of both worlds. He's a pretty knowledgeable guy and researches this stuff a lot, is always taking classes, etc. He's only 35 so not one of those old timers sticking to oil rules from 30 years ago that don't apply anymore. At any rate, the truck came with a synthetic blend Ow-20 so I'm going to stick with synthetic blend Ow-20. My 2007 silverado had pretty much nothing but dealer oil changes with their stock oil and AC Delco filters and never had any issues other than the oil consumption due to the AFM. I don't think it's worth wasting the extra money on upgrading any of that as long as you're on top of your maintenance. I would think a magnetic oil drain plug would be a good upgrade though.

Gmcant33 · March 21, 2015

Is synthetic blend the oil used for the 2year"free maintenance "?? And I believe 5000 miles is perfect for interval change before I would 3000 but I'm pretty sure now a days the 5000mi is the new 3000miles correct me if I'm wrong. And advice and knowledge is useful

chuckl1218 · March 21, 2015

I started using Mobil 1 and ACDelco filters (sometimes K&N or M1 filters) with my LS powered GM vehicles that recommended M1 (2001 T/A, 2004 GTO, 2006 CTS-V) and then just used it for everything else. Still have the T/A and GTO. So, when buying oil, I just stick with one brand and the appropriate viscosity. And yep, I buy it at Walmart. Never read anything that convinced me otherwise...

As far as intervals goes, I don't drive a lot of miles (work from home mostly), so I change at OLM or once a year at inspection time, whichever comes first. In Texas we have to have 'em inspected once per year; I have her inspected at a local oil change place. I bring the oil and filter, they do the dirty work. Also triggers me to rotate the tires.

Had my first oil change and tire rotation at the dealer due to timing with recalls and radio calibration.

Spurshot · March 21, 2015

Is synthetic blend the oil used for the 2year"free maintenance "?? And I believe 5000 miles is perfect for interval change before I would 3000 but I'm pretty sure now a days the 5000mi is the new 3000miles correct me if I'm wrong. And advice and knowledge is useful

I recall in 1968 when Texaco Havoline came out with an oil that they recommended a 5000 mile interval. All the other oil makers did the same around that time. I don't know where the low interval (3000-5000 mile) information is coming from for these trucks and the modern oil such as Dexos 1. It seems to be a historical number carried over by owners recollection, their father's teachings, etc.. But my old 99 1/2 GMT800 had an OLM interval that would light up around 4500 miles and it was based on pure mineral oil. My 2008 GMT 900 would go about 7000 miles on average before the OLM indicated an oil change was needed and it too was programmed for mineral oil. This new truck is programmed for the Dexos 1 syn/dino blended oil and it gets to about 9000 miles before indicating oil change.

chuckl1218 · March 21, 2015

Is synthetic blend the oil used for the 2year"free maintenance "?? And I believe 5000 miles is perfect for interval change before I would 3000 but I'm pretty sure now a days the 5000mi is the new 3000miles correct me if I'm wrong. And advice and knowledge is useful

Yes, synthetic blend that meets Dexos 1 standard is the oil that dealers are supposed to use for the "2 yr free maintenance".

Silverado-Hareek · March 21, 2015

Is synthetic blend the oil used for the 2year"free maintenance "?? And I believe 5000 miles is perfect for interval change before I would 3000 but I'm pretty sure now a days the 5000mi is the new 3000miles correct me if I'm wrong. And advice and knowledge is useful

5,000 is the new 3,000 for conventional oil. Synthetic blend can go 7,500 miles so your changing it early at 5,000 but you need to rotate your tires every 6,000 miles usually so I just stick with the 5,000 interval and synthetic blend. And yes the oil used with the free maintenance is synthetic blend. They'll always use that at the dealer even for paid oil changes unless you opt to pay for full synthetic.

Spurshot · March 21, 2015

5,000 is the new 3,000 for conventional oil. Synthetic blend can go 7,500 miles so your changing it early at 5,000 but you need to rotate your tires every 6,000 miles usually so I just stick with the 5,000 interval and synthetic blend. And yes the oil used with the free maintenance is synthetic blend. They'll always use that at the dealer even for paid oil changes unless you opt to pay for full synthetic.

SH,

Per the OLM on my truck, the recommended interval has gone to 9000 miles.

Since I do my own work, I see no correlation between tire rotation and oil changes. I rotate tires when needed based on mileage or condition and change oil when the light comes on. If I changed oil as often as I rotate tires, I'd be tossing out good oil and spending a lot more on oil.

newdude · March 21, 2015

Every 3k with a rotate at 5-6k. I have seen way to many problems roll through the shop (under warranty of course...) with cam actuators, actuator solenoids, and other oil based systems to even think about running long intervals. 5-10k miles I see them go, and they come in with clogged solenoid screens that are accompanied by check engine lights for cam phasing performance, timing chain failure, etc.

Silverado-Hareek · March 21, 2015

SH,

Per the OLM on my truck, the recommended interval has gone to 9000 miles.

Since I do my own work, I see no correlation between tire rotation and oil changes. I rotate tires when needed based on mileage or condition and change oil when the light comes on. If I changed oil as often as I rotate tires, I'd be tossing out good oil and spending a lot more on oil.

I may have worded that wrong. I was quoting the maintenance schedule in the manual so not necessarily the life of the oil. I do know at 5,000 miles, the oil on the dipstick is black and when it's fresh it is nearly clear so while the oil may have more life in it, I don't think I'm necessarily throwing out good oil per se but that's also why I don't spend the money on full synthetic because I know I'm going to just change it at 5,000 miles. I used to change the oil in my 2007 every 3,000 miles even though I could have gone 5,000 so I tend to change oil early to keep it fresh and protect the engine. In my opinion it's better for the engine to change oil more often than it is to use a synthetic versus a conventional but for a longer period of time. As for tire rotations, I agree "when needed" is a rule of thumb that should be followed but that seems to occur around 6,000 miles in my experience so I just do it all at 5,000 miles and be done with it. I drop it off at the mechanic, go to work, and pick it up at the end of the day. Saves me time and the hassle. This is one of those topics where everyone has their own preferred process but in the end, we're all probably not harming our engines in any way.

gone_fishing · March 21, 2015

My last few changes have been around 7300-7400 miles with was around 5% on the OLM. I now have about 34,800 miles total on the truck. I have been using M1 0W-20 and a Fram Ultra XG10575 oil filter.

Silverado-Hareek · March 21, 2015

Every 3k with a rotate at 5-6k. I have seen way to many problems roll through the shop (under warranty of course...) with cam actuators, actuator solenoids, and other oil based systems to even think about running long intervals. 5-10k miles I see them go, and they come in with clogged solenoid screens that are accompanied by check engine lights for cam phasing performance, timing chain failure, etc.

A coworker used to change the conventional oil in his 2006 Tahoe every 5,000 miles and he drove that thing to 198,000 problem free miles before selling it. 3,000 is ok on conventional but it's overkill with synthetic blends.

SlavO · March 21, 2015

I changed my oil at 950miles put mobil 1 0w-20 (Walmart oil) oil and mobil 1 filter. Then i did my 4 that came with the truck at 5,xxx 10,xxxx 15,xxx 20,xxx. Now i change it every other month on the 1st about 6,xxx miles with a tire rotation. .. im about at 30,xxx miles later today ... I've had it almost 11 months. Plan on driving it this way for 9 more years. Gl e1

Spurshot · March 21, 2015

I changed my oil at 950miles put mobil 1 0w-20 (Walmart oil) oil and mobil 1 filter. Then i did my 4 that came with the truck at 5,xxx 10,xxxx 15,xxx 20,xxx. Now i change it every other month on the 1st about 6,xxx miles with a tire rotation. .. im about at 30,xxx miles later today ... I've had it almost 11 months. Plan on driving it this way for 9 more years. Gl e1

I'm sure you will not have any problems caused by worn-out/contaminated oil and given no latent issues, I think 300,000 miles is perfectly reasonable to expect from one of these newer EFI engines. I would expect to have to do other things during that time, such as a water pump, maybe a A/C compressor and alternator. These components have sealed bearings and will eventually wear out. My experience suggests 150,000 is a good time to replace these components if they haven't failed...assuming you don't want to run to component failure. Don't forget the serpentine belt and all the idler pulleys as well. Something many people forget. All those little bearings will have gone around eleventy-million times by then. Maybe more.

Spurshot · March 21, 2015

My last few changes have been around 7300-7400 miles with was around 5% on the OLM. I now have about 34,800 miles total on the truck. I have been using M1 0W-20 and a Fram Ultra XG10575 oil filter.

~~You might reconsider that filter, based on what the crowd is saying on Bobistheoilguy.com~~

The Wix or Champ or relabled (Mobil, K&N, NAPA Gold, etc.) are the ones that seem to have the most consistent following on BITOG. They get pretty deep over there.

I stand corrected. The reviews on the Ultra are very good.