A comparison between Dexron-VI and Dexron-III(H)

The Critic · Jul 21, 2006

It should work better than a mineral Dexron-III(H), at least on paper.

As for manufacturers, Pennzoil just launched their Dexron-VI product today and it'll be avaliable at retail stores within the next week or two. I hope that price will be around $3.50/qt.

The Critic · Jul 21, 2006

quote:

I will say the GM lauded specification improvements in Dex VI have long been properties of good synthetic ATF - therefore same answer as above. GM is just moving one foot into the 21 century with a syn blend/grp III ATF.

This isn't true. Most of the synthetic ATFs on the market only differ in the baseoil used in comparison to conventional, mineral based fluids. The additive package is quite similar, and may not last any longer, hence the caution about extending fluid drains past the recommended interval.

With Dexron-VI, the fluid's additive package has been upgraded for long life. The fluid is much more shear stable by design. If you did a heads to heads comparison between Dexron-III(H) and Dexron-VI, you'll fine that Dexron-VI retains its viscosity much better.

stingray427 · Jul 22, 2006

So now Dexron 6 is available in the aftermarket where before it was only a dealer item?

Pablo · Jul 23, 2006

Mike - we have seen so few ATF UOA's, that I don't think we can determine much yet. They depend so much on the transmission and again we such a small database.

quote:

Help me here. AFAIK, the main difference between Amsoil UATF and a OTC mineral ATF (i.e. Pennzoil), is the quality of the baseoil, correct?

I would venture to guess Amsoil uses a notch better additive package.

quote:

And I think we're in agreement here that oxidation alone is not the sole factor in determining fluid life, correct? As other factors such as shudder, loss of shift feel, depleted additives, TAN, etc are all part of the equation. If such is the case, why are you assuming that a synthetic ATF alone will automatically extend the drain interval?

Oxidation is probably about 99% of the reason for degradation in ATF. Resistance to shearing is a property of the base oil as well. Sure some additives may prop up the base oil, but these VI's are subject to degradation as well.

MolaKule · Jul 23, 2006

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=56;t=000003

Oxidation inhibition and shear stability are the hallmarks of the DexronVI and SP fluids along with lower viscosities.

nascarnation · Jul 23, 2006

quote:

Originally posted by stingray427:
So GM contracted with some reputable companies in this case and didn't go with the lowest bidder? Dexron 6 GOOD STUFF

Petro Canada has been the Dex III factory fill supplier for at least 10 yrs.

Pablo · Jul 23, 2006

A modern synthetic ATF should have no problems with oxidation in any AT in good working order. GM is doing the right thing by bringing their specification up to date.

So Mola - you have studied DexVI? Is there anything truly unique about it?

stingray427 · Jul 23, 2006

Wait for Redline and Amsoil come out for equivalent for Dexron 6.

Ken2 · Jul 24, 2006

"Only 2005 and prior models that currently use DEXRON®-III may use DEXRON®-VI as a replacement."

Very interesting and very important.

For an Allison, I'd use a TES-295 ATF as my first choice. I include Amsoil's TES-295 clone, also.

Ken

Thatwouldbegreat · Jul 24, 2006

quote:

Originally posted by MolaKule:
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=56;t=000003

Oxidation inhibition and shear stability are the hallmarks of the DexronVI and SP fluids along with lower viscosities.

Is there a Specialty Formulations ATF that will work in a Dexron III Mercon V application?

Pablo · Jul 25, 2006

That is important. I wonder why it wouldn't work in a DexII app. for example. Different FM's, etc. Hmm...yes interesting.

dima · Jul 25, 2006

So, can I replace DexIII in my nissan sentra with new DexVI?

Brian Miller_dup1 · Jul 25, 2006

quote:

Originally posted by dima:
So, can I replace DexIII in my nissan sentra with new DexVI?

Great question!

It was my understanding (and others on this board) early on that DexVI was going to be backwards compatible with all the Dex fluids. If this were the case, we should be able to keep using it in our Nissan trannys that call for MaticD.

What about our power steering fluid (since I'm using DexIII(h) in it now?

Now I'm really confused

We could always ask the dealership

Brian

stingray427 · Jul 25, 2006

quote:

Originally posted by Brian Miller:

quote:

Originally posted by dima:
So, can I replace DexIII in my nissan sentra with new DexVI?

Click to expand...

Great question!

It was my understanding (and others on this board) early on that DexVI was going to be backwards compatible with all the Dex fluids. If this were the case, we should be able to keep using it in our Nissan trannys that call for MaticD.

What about our power steering fluid (since I'm using DexIII(h) in it now?

Now I'm really confused

We could always ask the dealership

Brian

stingray427 · Jul 25, 2006

quote:

Originally posted by Ken2:
"Only 2005 and prior models that currently use DEXRON®-III may use DEXRON®-VI as a replacement."

Very interesting and very important.

For an Allison, I'd use a TES-295 ATF as my first choice. I include Amsoil's TES-295 clone, also.

Ken

Same goes for the models that use Dexron III (h) too. :confused

stingray427 · Jul 31, 2006

quote:

Originally posted by The Critic:
I just noticed something. Why does it say except Saturn S-Series?

Those transmissions spec Dexron-III, so why wouldn't Dexron-VI be acceptable.

I don't see why not because Dex 6 covers all preding fluids.

The Critic · Aug 1, 2006

I just noticed something. Why does it say except Saturn S-Series?

Those transmissions spec Dexron-III, so why wouldn't Dexron-VI be acceptable.

stingray427 · Aug 1, 2006

quote:

Originally posted by The Critic:
Yep, I think it may be a viscosity issue as the overall viscosity is reduced with DexronVI, which may be an issue with the clearances.

But given that the transmission has about 100K (and is 10-yrs worth of 1-3 mi trips, lots of shifting), its really a toss-up as to whether the upgraded, "slightly less compatible" fluid would cause more damage. Agree?

I think I'll just pour in DexronVI and forget about it. After all, DexronIII thins to the starting viscosity of DexronVI within 10-15K anyway.

So forget about the Amsoil and Redline ATF and go with Dexron 6 from GM.

oilcan · Aug 2, 2006

So what could I expect in my 86 Ford C-6 that calls for DEXRON III?

unDummy · Aug 2, 2006

quote:

Originally posted by The Critic:
I just noticed something. Why does it say except Saturn S-Series?

Those transmissions spec Dexron-III, so why wouldn't Dexron-VI be acceptable.

I understand why the Dexron-VI can't be recommended for the GM 3309 and SPIII trannies, but I would think that those older Saturns would benefit from this upgraded ATF over DexronIII. GM cracks me up.

A comparison between Dexron-VI and Dexron-III(H)

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