SAE or synthetic

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Doppleganger

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My favorite is actually Mobil one..made from a pure gas in a. Lab.
Can't afford it though.
If it's good enough for the space shuttle..its Good enough for me!
Most synthetics are actually highly refined conventional oil!

I get it in the 5qt jugs for $25 at WalMart.

Costco's sells it in cases cheap too.
 

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@My78truck,

If your truck is earlier than late'80's and back do not use synthetic's due to the type of lubrication is not compatible with the kind of cam and lifters those engines use. They cannot get the proper friction reduction at the point of metal to metal contact...period. Unless your engine has roller lifters or you built your engine with rollers in it that previously had hydraulic lifters, do not use synthetic. It's not better for your engine just because it's newer.. Synthetic oils will wear you hydraulic cam and lifters right out in half the time if you had used regular SAE oil. It's the lubrication properties of the oil it is, SL, SJ, SM are all fine, and if I can dig up that paper there are other oils than just these. I contacted a oil "engineering" company because I wanted to find out what I should use and they sent me back a detailed report on current engine oils and trans fluids to. The paper explained what certain oils do and why. It was really interesting, if you are into engineering reports about oil. It gave you an idea what it looks like right where the lifter metal comes in contact with the metal surface of the cam goes through with conventional oil and synthetic lubricant.

Do not use any trans fluids other than Dextron III or Mercon or less, in any TH350, TH 400 or 700R4. If you use Dextron/Mercon V and up it will destroy the clutches in your transmission due to the fact that the abrasive material on the clutch disc is made up of certain compounds for the even wear and heat resistance, wear properties and compatibility with certain oils. Newer transmissions are not in any way like a TH350 and take a completely different fluid than older transmissions. It has nothing to do with the metal, it's the clutch disc's. Clutch disc's that can withstand newer transmission fluid don't exist so you have to stay with fluids for older transmissions. If you have a 4L60-80 new fluids are fine.
 

My78truck

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@My78truck,

If your truck is earlier than late'80's and back do not use synthetic's due to the type of lubrication is not compatible with the kind of cam and lifters those engines use. They cannot get the proper friction reduction at the point of metal to metal contact...period. Unless your engine has roller lifters or you built your engine with rollers in it that previously had hydraulic lifters, do not use synthetic. It's not better for your engine just because it's newer.. Synthetic oils will wear you hydraulic cam and lifters right out in half the time if you had used regular SAE oil. It's the lubrication properties of the oil it is, SL, SJ, SM are all fine, and if I can dig up that paper there are other oils than just these. I contacted a oil "engineering" company because I wanted to find out what I should use and they sent me back a detailed report on current engine oils and trans fluids to. The paper explained what certain oils do and why. It was really interesting, if you are into engineering reports about oil. It gave you an idea what it looks like right where the lifter metal comes in contact with the metal surface of the cam goes through with conventional oil and synthetic lubricant.

Do not use any trans fluids other than Dextron III or Mercon or less, in any TH350, TH 400 or 700R4. If you use Dextron/Mercon V and up it will destroy the clutches in your transmission due to the fact that the abrasive material on the clutch disc is made up of certain compounds for the even wear and heat resistance, wear properties and compatibility with certain oils. Newer transmissions are not in any way like a TH350 and take a completely different fluid than older transmissions. It has nothing to do with the metal, it's the clutch disc's. Clutch disc's that can withstand newer transmission fluid don't exist so you have to stay with fluids for older transmissions. If you have a 4L60-80 new fluids are fine.

WOW!!! Thanks for all the info. I will definitely be using good 'ol dino fluids. Problem I have now is I do not know whether dino or synthetic is in my transmission after rebuild. AAMCO doesn't seem to have their S**T together enough to annotate what they put in so I know. So, once I can get the vent window seal in (that has been on order for over 1 month), and the 43 year old window glass is not flopping around inside the door, I can take it and get it drained and have dino put back in it.
 

My78truck

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Probably going to get chastised for this, but how does anyone feel about Penzoil non-synthetic. This is what I have used in the past. Was told to steer clear of Quaker State years ago - I guess because of deposits.

Also, what exactly is in a "high mileage" oil that isn't in a standard/conventional oil? Or is that just a money making/marketing scheme.
 

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The way most people drive their cars each day,a conventional is fine.As long as oci are under 5k.And as far as older model engines are concerned,oci at 4k or less.Syns give you extended oci and faster flowing in colder weather even comparing say,conv. to syn in the same temp. grade/viscosity.Flow rate is different between a conv. oil and a syn. oil and that's the bigger benefit along with extended oci.And as far as older gm trannys go,the dex VI that is compatible with the older dexrons is a little thinner viscosity tho and I wont run it.
 
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@My78truck,

If your truck is earlier than late'80's and back do not use synthetic's due to the type of lubrication is not compatible with the kind of cam and lifters those engines use. They cannot get the proper friction reduction at the point of metal to metal contact...period. Unless your engine has roller lifters or you built your engine with rollers in it that previously had hydraulic lifters, do not use synthetic. It's not better for your engine just because it's newer.. Synthetic oils will wear you hydraulic cam and lifters right out in half the time if you had used regular SAE oil. It's the lubrication properties of the oil it is, SL, SJ, SM are all fine, and if I can dig up that paper there are other oils than just these. I contacted a oil "engineering" company because I wanted to find out what I should use and they sent me back a detailed report on current engine oils and trans fluids to. The paper explained what certain oils do and why. It was really interesting, if you are into engineering reports about oil. It gave you an idea what it looks like right where the lifter metal comes in contact with the metal surface of the cam goes through with conventional oil and synthetic lubricant.

Do not use any trans fluids other than Dextron III or Mercon or less, in any TH350, TH 400 or 700R4. If you use Dextron/Mercon V and up it will destroy the clutches in your transmission due to the fact that the abrasive material on the clutch disc is made up of certain compounds for the even wear and heat resistance, wear properties and compatibility with certain oils. Newer transmissions are not in any way like a TH350 and take a completely different fluid than older transmissions. It has nothing to do with the metal, it's the clutch disc's. Clutch disc's that can withstand newer transmission fluid don't exist so you have to stay with fluids for older transmissions. If you have a 4L60-80 new fluids are fine.


I don't even know where to start with this... almost everything in this post is wrong in one way or another.

A modern synthetic oil with a ZDDP additive or a synthetic designed specifically for flat tappet camshafts will work just as well or better than an equivalent conventional oil. Please actually look at all of the information that @GMFORLIFE has posted in here already on this subject. If you have contradictory information, please actually site a source. You are stating things as "facts" that are just not so.

If your transmission has been rebuilt in the last 30 years, it is going to have the same clutch material that is used in a 4L60e or 4L80e... In fact the 700R4 and 4L60e use the same clutches(for the most part). The TH400 and 4L80E also share a few clutches. Also, ACDelco specifically calls out that Dex VI is a fully backwards compatible replacement for Dextron II and Dextron III. https://www.acdelco.com/parts/oils-fluids/gm-oe-dexron-vi-transmission-fluid

It is basically a fully synthetic version of Dextron III. I personally use Valvoline Max-Life ATF in both my 1980 K25 w/TH400 and my 2011 Suburban w/6L80E and will probably run it in the 4L80e when it gets swapped in too. I've had it in there for years of towing, wheeling, and generally beating on it and the fluid is still cherry red and unburnt. No slippage and still shifts perfect. Judging by the amount of oil and sludge built up all over the transmission and T-case when I pulled them out a few weeks ago, I'm pretty sure it's the original unmolested trans too.

The synthetics are much more resistant to high temps and that is exactly what you want and need in a hard working transmission.
 

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Only thing I was ever told about Quaker State was they used recycled oils....cleaned and then additives added. That was the reason why all the shops I knew (years ago) wouldn't touch it if they were 3qts down and knocking.

My square's new motor is a 97 5.7 with a roller cam and Edelbrock vortec heads. After break in on Castrol dino, we're going full synthetic.
 

82sbshortbed

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I think it's a big marketing gimmick. Don't think there's much of a difference between the oils. As long as you get the right weight of oil you'll be good. Remember slick50? That was the best **** you could ever get and would save any engine. You could put some in and drain the oil then run it with no oil in it. Lol

Now I don't think anyone uses that **** anymore. Just keep it changed regularly and you'll be good.
 

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I think it's a big marketing gimmick. Don't think there's much of a difference between the oils. As long as you get the right weight of oil you'll be good. Remember slick50? That was the best **** you could ever get and would save any engine. You could put some in and drain the oil then run it with no oil in it. Lol

Now I don't think anyone uses that **** anymore. Just keep it changed regularly and you'll be good.
Slick 50 was marketed/owned by "Quacker"State and advertised that the engine wear was because of oil drainback to the pan and on startup was when most wear occurred.The FTC made them try to prove this,and couldnt by any available provable means.They put the brakes on this claim.Slick 50 is not heard of much anymore...FTC lawsuits are supposed to help protect against misleading/false advertising.The Slick folks couldnt show that engine wear,or prove that their formula did what they claimed
 

82sbshortbed

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1986

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I prefer cheaper oil changed OFTEN, rather than expensive oils left too long.

I rode 4 stroke dirt bikes for years.. '02 - '10 I had three KTM's, 520, 525 and a 450. These are close tolerance engines and factory insists
on Motul synth only. Four stroke motorcycle oil has higher heat ratings, just so you know the difference between automotive oils.
Well I never ran the recommended oil. I always bought the regular Honda brand non-synth oil. But I changed oil really often, like every half dozen rides but sometime after one ride... if it was long and hot and gnarly, like slow going woods riding or anytime in silty dist. My 520 had somewhere
around 160+ hours on it and it was like new inside. The guy that bought my 525 ran the hours over 200 (he remained on the same oil regime I gave it)
and when he failed to adjust the exhaust valve and it wouldn't start, his mechanic 'friend' tore the top end apart only to learn the valve needed adjustment... and also that the cylinder honing marks still looked like new. Over 200 hrs..? I wouldn't have believed it if I didn't see it for myself.
 

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1986

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And even Duralube,who once claimed you need only add it every 50k changed that recommendation in later years to adding it at every oil change. The old time snake oil salesmen have evolved into multimillion dollar modern fringe snake oil salesmen.lol
 

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