Extended Oil Change ?

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I have two corvettes that were only driven about two hundred miles each this year due to illness. Normally I change the oil each fall but with low miles is it okay to wait until next spring to change oil ? Dino oil in 72 vette and synthetic in 2003.
 
Originally Posted By: yankees1
I have two corvettes that were only driven about two hundred miles each this year due to illness. Normally I change the oil each fall but with low miles is it okay to wait until next spring to change oil ? Dino oil in 72 vette and synthetic in 2003.

I would change the dino out and keep the synthetic, but that's just me.
 
No reason to change whatsoever. The oils have anti-acids in them and the contamination comes though hours of use not hours of sitting. Oil is a stable paraffin doesn't care about time sitting in a pan.
If you over-change you will cause HARM. So, fa gitaboudit!

If you put about 3k in three years go the three years. Forget Annual OCI. Save your worries for the crisis around the corner - not this
smile.gif
 
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Any hard evidence out there that doing an annual oil change on a low mileage vehicle WILL result in HARM?

If this were really the case, shouldn't there be a warning in current owner's manuals to warn users that in the event they have too few miles in a year, to ignore the manufacturer's written owner's manual guidance of doing an annual oil change? What if some owner had only 200 annual miles but did that with weekly 4 mile trips (2 miles to the shopping center...then drive back 1-2 hours later)?

I'm in the same boat as the OP. 800-1200 miles per year on my 1999 (always a minimum of non-stop, 15-20 miles drives). I change the M1 0w-40 annually. Nothing I've read says this is doing HARM. I can afford the extra $20/yr for an M1/FUG oil change. I keep in touch with a number of other 4th gen LS1 owners who do a similar maintenance routine. All these cars are under 30K miles and 15-20 years old now. Some drive as little as 200-400 miles per year...maybe half a dozen uses per year. No issues on any of the engines.

If it were me, I'd probably change the dino oil on the OP's Vette. The synthetic at only 200 miles is really not an issue not changing until more miles rack up. I think you're fine no matter what you do on either of them. New cars can sit on lots for up to 2 years at time, under 200 miles and on factory conventional/syn blend fills. They don't seem to suffer for it...though I doubt anyone tracks such vehicles through end of engine life to see if there were "problems" years down the road.
 
My MIL drives low mileage on her CRV and was doing yearly changes with conventional oil and the engine seems fine.
 
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When I had my toy I easily went 1 to 1-1/2 years between changes. When I did start it I tried to drive at least 10-15 miles to heat it up but the UOA were always fine.

No harm in waiting
 
Originally Posted By: ARCOgraphite
No reason to change whatsoever. The oils have anti-acids in them and the contamination comes though hours of use not hours of sitting. Oil is a stable paraffin doesn't care about time sitting in a pan.
If you over-change you will cause HARM. So, fa gitaboudit!

If you put about 3k in three years go the three years. Forget Annual OCI. Save your worries for the crisis around the corner - not this
smile.gif



^ This. Especially with ONLY 200 miles!
 
I have a 1992 Miata that I have had since new. I only put about 300 miles a year on it, and is garage kept. But every spring I change
the oil & filter, even thou I know I don't have to. With the deals on oil & filters that I get from joining this site, it cost me
less than $10 to put syn blend in. Gives me a reason to tell my wife I can't help her with spring cleaning, I have to change the oil.
smile.gif
 
It is true that there's a 2007 mfg's fleet study that concluded engine wear rates were the highest early in the oil change interval. After 3K miles wear rates continued to decline until the oil was "officially" used up (TBN, TAN, viscosity, or other factors). Still, the period of higher wear likely varies considerably between oils, engines, and duty cycle. Apparently, the protective, anti-wear chemical tribofilms get fully/partially removed from the application of fresh detergents following an oil change. One size doesn't fit all.
 
Originally Posted By: 69GTX
It is true that there's a 2007 mfg's fleet study that concluded engine wear rates were the highest early in the oil change interval. After 3K miles wear rates continued to decline until the oil was "officially" used up (TBN, TAN, viscosity, or other factors). Still, the period of higher wear likely varies considerably between oils, engines, and duty cycle. Apparently, the protective, anti-wear chemical tribofilms get fully/partially removed from the application of fresh detergents following an oil change. One size doesn't fit all.


If that was true why wouldn't we all be running oil forever and just use an additive to take care of TBN/TAN?
 
Originally Posted By: JohnnyJohnson
Originally Posted By: 69GTX
It is true that there's a 2007 mfg's fleet study that concluded engine wear rates were the highest early in the oil change interval. After 3K miles wear rates continued to decline until the oil was "officially" used up (TBN, TAN, viscosity, or other factors). Still, the period of higher wear likely varies considerably between oils, engines, and duty cycle. Apparently, the protective, anti-wear chemical tribofilms get fully/partially removed from the application of fresh detergents following an oil change. One size doesn't fit all.

If that was true why wouldn't we all be running oil forever and just use an additive to take care of TBN/TAN?

It appears to be something that's not true but often repeated here on Bitog. Take a look at this thread:

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4443010/1

Originally Posted By: Shannow
That paper keeps getting trotted out as proof of something that the paper never tested nor demonstrated.

They took a bunch of used oils, some of which were utterly shagged, had thickened excessivly and had poor TBN.

Then they use a contacting surface tribometer and measured the establishment of the tribofilms with new and progressively used oil. The used oil formed tribofilms on fresh metal surfaces quicker than fresh.

This is entirely to be expected, as the first part of the laying down of tribofilms involves partial destruction of the ZDDP/Mo into more reactive species...some additive companies put a lot of different elemental "variaties" in so that there are different points of activation.

So the oil with the most already partially reacted species in it produced the best tribofilms the earliest...exactly as expected.

The Used oil, excessively thick, wiht no TBN to speak of was not necessarily the best oil to have in the engine. Extrapolating the limits (surface tribometer) of this study INTO that realm is really stretching the bow a bit (well a lot).

And at OCI, the quote that you have provided assumes that ALL of the tribofilm is removed to fresh metal (not true, never seen anything on that).

As to the thought process...

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4060600/1
 
If they were mine Id take them out and heat them up enough to burn off any condensation then put them back in storage until I could enjoy them again.


UD
 
Leave it alone. Changing the oil before winter isn’t going to help anything, it’s just going to be sitting in the bottom of the pan regardless.

That would be like washing a Jeep absolutely spotless, waxing, polishing, tire shine, etc. and then go drive it through 2 feet of mud for an hour.

Doesn’t make a difference.
 
What I posted above was in fact true. And Shannow seems to agree. There is more wear early in the OCI's as "some" of the Tribofilms get removed. Whether you run your own oil to past TBN expiration is your own choice. I wouldn't. I merely brought this up to show that wear rates do start off higher in an OCI. It's probably very costly to quantify what those "wear rate" differences might be over an engine's life. Probably not much.

This is entirely to be expected, as the first part of the laying down of tribofilms involves partial destruction of the ZDDP/Mo into more reactive species...some additive companies put a lot of different elemental "variaties" in so that there are different points of activation.


And one should clearly change their oil before TBN/TAN get too close to turning the wrong way. Nowhere did I agree with pushing TBN into the ground while running on thick/oxidated oil from 8K to 20K miles depending on your vehicle/oil/usage. And my own OCI's never go past 4K-4.5K on synthetic oils.
 
... Not to mention dry starts after changing the oil... and chance of installing a bad filter (where the existing was fine. I recall I spun a bearing on an old suburu Loyal 1.8L changing the oil in the dead of winter. Engines Wasn't knocking BEFORE I changed the oil.

The oil get oxidized and the EP /AW get used up. On a UOA, You will still see the high ppm for Zn, but its inactive - used up. Oil does have to be changed but not too soon.

I was an over zealous oil changer and you saw what happened to my cars.

It can be a hard habit to loose.
 
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