The truth about oil change intervals

Haufski762 · April 3

Pretty good video. @ 26:00 they talk about it.

https://www.youtube.com/watch?v=fu7PlRsqMyA&ab_channel=Dave'sAutoCenter

Grumpy Bear · April 3

Thanks for the video, Dan. :thumbs:

3K is an excellent 'Eyes Wide Shut" number, that is, if you not testing being implied, and as he, Lake, alluded to.

I smiled at the way he sidestepped the 'normal oil usage' question AND drew on the OEM average consensus instead of his experience. Which would have told a much different story.

GETGONE · April 4

Find Lake's channel. He has LOTS of good oil info there and testing and results. Been following him for several months now.

Haufski762 · April 5

The part about the manufactures getting eco credits or whatever they call them from .gov was interesting. They tell you to change your oil at a magic number (5000) just to get those credits.

If oil analysis was cheaper it would be the way to go.

Grumpy Bear · April 5

16 minutes ago, Haufski762 said:

The part about the manufactures getting eco credits or whatever they call them from .gov was interesting. They tell you to change your oil at a magic number (5000) just to get those credits.

If oil analysis was cheaper it would be the way to go.

C.A.F.E credits. Quality UAO's do cost a bit which make 3K or shorter OCI's the way to hedge your bets. When I first started driving in the 60's a 3K OCI was considered an extended drain interval, :crackup: and it was considering the mineral un-hydrogenated, solvent dewaxed, high Sulphur shelf oils we had at the time. 2K had been the standard for decades before. In my area we did 1K but oil cost 20 cents a quart and a CASE was 24 quarts. Dad had a cow if it went 1500 miles. Besides, it was part of our weekend routine.

The minute you fire that motor after a fresh change that oil is chemically degrading. How quickly depends on 1.) the chemistry which includes not just the add package but the base oil selection as well. 2.) How it is used, operationally and environment. It also depends 3.) on the motor's health. Mainly the ring seal as it is not just heat and oxygen attacking the oil but byproducts of combustion seeding the oil for degradation. In a world that believes a quart in a thousand past the rings is 'normal' even a new motor can be hard on oil. Dad would have beat that kind of stupid out of me before I was five. Quart in a thousand my eye. Out of all the GM's I've owned I've had two that used oil between changes. Normal it isn't.

So, the better the seal, the better it's treated and he more robust the oil the longer it last.

Grumpy Bear · April 7

A UAO tells you two things. 1.) the condition of the motor. 2.) The condition of the oil.

Of those two, the oil is more of a concern to me.... personally. Opinion varies greatly.

1.) Is it in viscosity grade. 2.) Does it have reserve alkalinity above the acid value. 3.) Is it clean.

Most people's habits and environment are pretty steady Eddy. So continuous UOA's, once a baseline is established are wasteful. IMHO. Find your mark early and spot check from time to time. Peg your OCI to the data. Not some arbitrary number...UNLESS you just don't want to or can't afford to test. If either is the case, low ball it.

If you keep those three listed things in check, the rest of them are likely to stay in line. Remember. Most people never even look and do quite well.

Edited April 7 by Grumpy Bear

64BAwagon · April 7

I changed the oil in my L8T Silverado 3500HD this last week. I had almost 4800 miles on this oil but around 3000 of those miles were pulling/carrying 13,000 of cargo. I had every intention of drawing a sample and even had the Blackstone container on my workbench. I pulled the drain plug and then realized I left it on the counter. Knowing that at my age it was unlikely I could shimmy my husky frame out from under the truck and grab the container in time to get a valid sample I decided to do it "next time" Just as you said, I was just looking for a "baseline" on a new vehicle after a hard run on its second oil change.

At this point of my life I have the luxury of time to shop sales and clearances. This puts an 8 qt oil change with GM branded Dexos 5W30 and an AC UPF63R filter in the arena of under $25. A Blackstone analysis is over $30. For me its more economical to just do 5000 miles intervals, assuming my baseline test comes back favorable.

diyer2 · April 7

"Of those two, the oil is more of a concern to me.... personally." I agree.

Why I changed to Amsoil OE oil. I thought it was a good upgrade at a fair price. Considering going to 5K OCI's. Amsoil says the OE oil is good for 7500, 5k shouldn't be a problem. Do I believe them? Well a UOA would answer the question, not gonna happen.

Grumpy Bear · April 7

11 minutes ago, 64BAwagon said:

.........................................................assuming my baseline test comes back favorable.

I used 5K as a touchstone for years. Easy to remember and incorporate with things like tire rotation.

Then GDI happened. I have several GDI motors. Each has a different OCI and a different oil. Not the way I would prefer but I learn slowly sometimes.

The pickup has an Ecotec3 4.3 and for the most part has been a Red Line HP motor most of its life and I change it on 5K OCI's. It's near 180K now and never been a lick of trouble. Uses little oil and in fact Iooks pretty good when I take it out. This is also an E-85 motor and has been for about two years now. High solvency non-Dexos oil and clean as a whistle inside and out.

The wife's Terrian is an Ecotec 2.4 I-4 that also received 5K OCI's, but I used whatever Dexos1Gen2 oil. Quaker State UD and Kirkland Signature for the most part. These are dry oils both. It was oil usage free over that length for 80K miles and since then I have fought oil consumption, stuck rings and plugged ring drains and cam phaser screens for the remainer of its 241K and still fighting it. It's currently on 1K OCI's and looks worse at 1 K than the pickup at 5K. I've done UOA on both.

Both of these motors have TSB's out on ring issues as they shared the same ring "type" and piston ring land design.

Wife has a Buick Verano with the same Ecotec 2.4. That motor lives on Ester base oil (Red Line HP) and short 3K or once a year changes. No labs on that one but lesson learned. If she ever starts driving it as her daily, I'll sneak up on the OCI with UOA's then sample maybe every 25K.

I've had Honda's on Red Line HP at 7.5K OCI's go forever and stay clean. And family with old Buick 3800's SPFI on whatever swill they could pour in on 7.5K or longer go over 500K.

Point? Each of these lives with a different driver, has a different design, uses a different oil and needs a different OCI. The ones we got right are trouble free, those we didn't......