Motor Oil
Race Director
Joined: Aug 2000
Posts: 11,470
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What are your cold & hot oil pressure readings? If your motor is about worn out go up a grade. If it is still making proper oil pressure on the factory recommended grade then stay with it. My car ('86L) has about 125k miles and good oil pressure on 10w30 in Texas heat. It really is up to you, these are JUST small block chevys and are kind of hard to kill unless you beat them really hard.
- in a nutshell, just follow the owners manual, and all's good.
Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
not sure where you're going with this, but "for THEM," i'm guessing would only apply during the warranty period - back then, as I recall, 3 years/36K miles. since my owners manual covers maintenance up to, and sometimes exceeding 100K miles, anything outside the warranty period, they are doing for "my benefit" and what's best suited from a maintenance standpoint. not sure how the factory can even define and cover "the zenith." if they could, that would just redefine it as the norm. someone will always push the envelope and that, the manufacturer can't control. not sure i know of any oil related engine failures, outside the warranty period, due to the owner following the manufacturers recommended maintenance and maintenance schedule, so the whole thing is subjective - i really don't care who they figured it out for - them, me, or anyone else. it works for me and one less thing i have to think about. peace.
Race Director
Joined: Aug 2000
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We have also wondered why we have to put in an additive every 15K for my Powerstroke which uses the regular green stuff for coolant. Is that the best idea? Well, it depends. The dealership would have to stock that coolant, which they do and the small bottles of the additive. International uses a more robust coolant which has better life and no need additives. International made that engine for trucks which Ford bought. Truck shops have ELC for other trucks. Ford dealerships might not want to stock yet another coolant for a few diesel vehicles or so a suspicious man like myself would think. Test strips International recommends show the green stuff with the additive every 15K is barely adequate.
Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
Sorry it's confusing you but the PRINCIPLE is that we need to be more skeptical about why something is recommended instead of simply swallowing whatever they put before us without questions.
Race Director
Joined: Aug 2000
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, some things in life you need to be skeptical of, but i'm not sure this is one of them. 
Last edited by Joe C; Oct 6, 2018 at 11:57 PM.
Melting Slicks
Joined: May 2018
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From: Question Government
Team Owner
Joined: Jul 2004
Posts: 28,474
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From: Hartford WI
the factory figured all this out for us. one less thing we need to worry about
Last edited by aklim; Oct 7, 2018 at 10:59 AM.
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Team Owner
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From: Hartford WI
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I got to say it is a pretty good crutch for those who cannot mentally discipline themselves to do it.
Drifting
Joined: Oct 2015
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From: Shit Creek, USA
Team Owner
Joined: Jul 2004
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From: Hartford WI
Le Mans Master
Joined: Jun 2009
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From: South Dakota
Shelf life has a lot of different answers.
Most dino oils seem to have a shelf life that is affected by temp extremes even in a sealed container. Extreme temps may not even be that extreme as I read one manufacturer was claiming the below freezing could change their oil. The guesstimate of about 5 years may be about right for normal inside storage.
Synthetics may be a different story. I have read similar to the dino oils to no degradation at all. Mobil 1 stated no shelf life degradation under closed container storage. My belief is that synthetics may last much longer than dino oil and with normal storage conditions may last a long time without degradation.
The more I read about oil shelf life the more confusing it gets because different manufacturers have different statements and some statements are biased toward selling more oil.
Good luck.
Most dino oils seem to have a shelf life that is affected by temp extremes even in a sealed container. Extreme temps may not even be that extreme as I read one manufacturer was claiming the below freezing could change their oil. The guesstimate of about 5 years may be about right for normal inside storage.
Synthetics may be a different story. I have read similar to the dino oils to no degradation at all. Mobil 1 stated no shelf life degradation under closed container storage. My belief is that synthetics may last much longer than dino oil and with normal storage conditions may last a long time without degradation.
The more I read about oil shelf life the more confusing it gets because different manufacturers have different statements and some statements are biased toward selling more oil.
Good luck.
Last edited by QCVette; Oct 17, 2018 at 05:42 PM.
Race Director
Joined: Aug 2000
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i'm thinking it would be the additives and not the oil that has the shelf life. as I recall, the molecular structure of oil is fairly stable. that's why motor oil can be recycled, or re-refined. remove the chemical impurities, add fresh additives, and technically, it's good as new. - 
Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
i'm thinking it would be the additives and not the oil that has the shelf life. as I recall, the molecular structure of oil is fairly stable. that's why motor oil can be recycled, or re-refined. remove the chemical impurities, add fresh additives, and technically, it's good as new. -
Le Mans Master
Joined: Aug 2017
Posts: 6,942
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From: New Jersey
The heat cycling it gets in the crankcase for a year if you only drive it occasionally is probably much worse than it sitting sealed on a shelf and you then deciding to dump it in after a couple years... The problem as I remember it is that the additive package tends to settle out of suspension and can't be put back by shaking after a while. Synthetic or regular, it flocculates. Again, people worry about this too much. If it's 10 years old maybe, 5 I wouldn't worry about if it were unopened unless it explicitly stated an expiration date on the bottle... and even then that is to cover their tails just in case more than anything.