Performance-oriented Dexron III fluids?

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What are some proven fluids for track/race use in a GM manual transmissions requiring Dexron III? The usual suspect always seems to be Red Line D4 ATF but I'm open to other options. Motul Multi ATF, Schaeffer 204SAT All Trans Supreme, Renewable Lube Bio-SynXtra ATF PLUS, and Amsoil SSS all look stout on paper but don't seem to be specifically marketed as having a focus on extreme usage, racing, etc.

Is something like Mobil Delvac 1 ATF worth considering? It has an impressive list of approvals and is designed for heavy duty usage...but doesn't list Dexron.

The hottest temp the transmission has ever reported to the Performance Data Recorder is 250 F while out on track. The car has a dedicated transmission cooler and I change the MTF based on Chevy's recommendation of every 15 track hours. Previous Blackstone reports on the GM fluid have always been fine except for viscosity being a touch low.



The factory MTF is GM 88861800 which is made by Petro-Canada. KV @ 40 is 34 cSt and KV @ 100 is 7.7, giving an [insane] calculated VI of 207.

Car in question is below.
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High Performance Lubricants "Blue" ATF is a Dex III synthetic fluid.

KV40.............32.4 cSt
KV100...........6.9 cSt
VI..................184
 
Originally Posted by MolaKule
Redline MT-LV would be my choice since it has a good dose of AW in the additive package.

MT_LV



^This.

Redline make the goodness.
 
Originally Posted by MolaKule
Redline MT-LV would be my choice since it has a good dose of AW in the additive package.

MT_LV



Interesting, I've never seen this before. Their application guide doesn't recommend this, it actually recommends D4 ATF instead. Looking at the spec sheet, it appears to be about 10% thinner than other Dexron III fluids. Red Line also doesn't make any mention of "works in Dexron III applications" or anything like that...so I'm a bit leery.
 
I use the D4 ATF in my 2016 Chevy/Holden SS Sport Sedan 6 Speed manual

No track time to report but shifting was improved over GM fluid
 
I don't know anything about lubricants and hydraulic fluids but...

your Corvette's picture at the limits of lateral adhesion is really neat!
 
Originally Posted by splinter
I don't know anything about lubricants and hydraulic fluids but...

your Corvette's picture at the limits of lateral adhesion is really neat!


Hehe, that's what we call "full send".
 
Redline D4 ATF, Amsoil ATF torque-drive, Mobil 1 ATF are all well-tested for GM manual transmissions requiring DEX III.....ideally not those in original trans with paper lined friction rings. The only fluid Tremec recommends in the old T56's requiring Dex III is the Mobil 1 ATF.

The GM 88861800 is ok but it shears quickly. It would have to be changed fairly often. From one old thread I recall a Corvette owner ran it 10,000 miles on a fairly hard driven car. It sheared down from 7.5 to 5.5 or less. I used this stuff but don't drive hard and change it every 5,000 miles (4-5 yrs for me).
 
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Originally Posted by 69GTX
Redline D4 ATF, Amsoil ATF torque-drive, Mobil 1 ATF are all well-tested for GM manual transmissions requiring DEX III.....ideally not those in original trans with paper lined friction rings. The only fluid Tremec recommends in the old T56's requiring Dex III is the Mobil 1 ATF.

The GM 88861800 is ok but it shears quickly. It would have to be changed fairly often. From one old thread I recall a Corvette owner ran it 10,000 miles on a fairly hard driven car. It sheared down from 7.5 to 5.5 or less. I used this stuff but don't drive hard and change it every 5,000 miles (4-5 yrs for me).



My last analysis on it after 15 track hours and ~7600 total miles showed 4.89! Particulate matter was fine and actually very consistent with the previous one.

What about the Mobil Delvac 1 ATF? It's not a Dexron III but has similar viscosity to the non-Delvac version.
 
Originally Posted by dparm
Originally Posted by MolaKule
Redline MT-LV would be my choice since it has a good dose of AW in the additive package.

MT_LV



Interesting, I've never seen this before. Their application guide doesn't recommend this, it actually recommends D4 ATF instead. Looking at the spec sheet, it appears to be about 10% thinner than other Dexron III fluids. Red Line also doesn't make any mention of "works in Dexron III applications" or anything like that...so I'm a bit leery.



Be leery if you must but ATF does not have the friction modification nor the doses of AW additives that do dedicated MTF's.
 
Originally Posted by MolaKule

Be leery if you must but ATF does not have the friction modification nor the doses of AW additives that do dedicated MTF's.



Yes, understandable and I always thought it was weird that the MTF they specify is also Dexron III, unless I've misunderstood. GM does label their fluid as "manual transmission and transfer case fluid". In the end, it looks to be roughly a 70w80.

You're saying the lower viscosity is not something you'd be worried about? I assume you are okay with it because it will hold viscosity much better than the OEM fluid will.
 
Why not consider any MTF in 75W80 - 75W110 for its higher KV@40*C and components protection in this manual trans ?
 
Originally Posted by dparm


...You're saying the lower viscosity is not something you'd be worried about? I assume you are okay with it because it will hold viscosity much better than the OEM fluid will.


Right, the long-term viscosity will hold up better and not shear down.
 
Originally Posted by zeng
Why not consider any MTF in 75W80 - 75W110 for its higher KV@40*C and components protection in this manual trans ?


Where did you ever see a 75W110 MTF?

The suggested fluid is within the range of viscosities in which the transmission was designed to operate.
 
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I don't know why people recommend LV fluids when the original spec is higher viscosity.
Because the OE will shear down? So you want your fresh fluid to be already that low in VI? Makes no sense.
I want something that starts with OE specified VI and... stay there as long as I am using it.
AMSOIL Signature Series (non fuel efficient), Red Line D4...
 
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I believe Royal Purple Synchromax is specifically designed for this. I've run it in 2 Corvettes with Tremecs as well as E39 M5, and also track days and have had no issues.
 
Originally Posted by SoNic67
I don't know why people recommend LV fluids when the original spec is higher viscosity.
Because the OE will shear down? So you want your fresh fluid to be already that low in VI? Makes no sense.
I want something that starts with OE specified VI and... stay there as long as I am using it.
AMSOIL Signature Series (non fuel efficient), Red Line D4...

+1
Other parameters being equal, a viscosity-sheared say, Dexron III (or equivalents) at a residual operating viscosity of "X.5" cSt offers thicker and higher MOFT than an unused brand and shear stable LV Dexron VI at operating viscosity of "X.3" cSt . Both at similar operating temperatures .
 
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