I ran into this last year when I changed the fluid in the 4Runner. I, too, found the recommended Dex VI a little light (thin). Did some research and found that Mercon V and Dex III were very close in spec. Went with Mercon V and never looked back.
Where to get real Dexron III ?
- Thread starter das_peikko
- Start date
- Status
Originally Posted by Dave1027
Originally Posted by dave1251
Then your car can't run after 10K miles of DEXRON III use if it can't run on DEXRON VI. So you must be the guy doing a drain and fill every 5K.
Nope. Wrong again.
No your wrong because DEXRON III is thinner then VI except within the first 10K miles. So once again you have the most unique car in the world which does run right.
Originally Posted by dave1251
Then your car can't run after 10K miles of DEXRON III use if it can't run on DEXRON VI. So you must be the guy doing a drain and fill every 5K.
Nope. Wrong again.
No your wrong because DEXRON III is thinner then VI except within the first 10K miles. So once again you have the most unique car in the world which does run right.
Originally Posted by ka9mnx
I ran into this last year when I changed the fluid in the 4Runner. I, too, found the recommended Dex VI a little light (thin). Did some research and found that Mercon V and Dex III were very close in spec. Went with Mercon V and never looked back.
Yet another individual which physics do not apply.
I ran into this last year when I changed the fluid in the 4Runner. I, too, found the recommended Dex VI a little light (thin). Did some research and found that Mercon V and Dex III were very close in spec. Went with Mercon V and never looked back.
Yet another individual which physics do not apply.
If you want "real" Dex III then you need to travel back in time to when GM still used it. ACDelco had several suppliers for its branded Dex III I would surmise. In these parts I think PetroCan even supplied some of it. Now everyone and their dog has a fluid that is compatible with the old Dex III as there is nothing fancy about it.
MolaKule
Staff member
Originally Posted by hatt
Originally Posted by MolaKule
...Let's look at some of the Dexron III(H) and Dexron VI stats. Dexron III(H) is 1.4 cSt higher at 100C than Dexron VI but:
Starting Viscosities@100C
exron III(H) 7.3 cSt, Dexron VI - 5.9 cSt
Shear Stability (~ 10k miles): Dexron III(H) - 4.5 cSt, Dexron VI - 5.8 cSt
Shear Stability .(>=35k): Dexron III(H) - 4.3 cSt, Dexron VI - 5.5 cSt
Dexron III(H) has dropped over 2.8 cSt while Dexron VI has remained stable with only a 0.4 cSt drop. Dexron VI is superior in terms of viscosity stability.
Friction Modification Stability: In Dyno tests, Dynamic friction coefficient change: Dexron III(H) -~ 3%, Dexron VI - ~ 0.05%. Dexron VI is superior in terms of Dynamic friction coefficient stability.
Dexron III(H) uses older Anti-Oxidant and Metal Inhibitor chemistry. Dexron VI uses modern Anti-Oxidant and Metal Inhibitor chemistry.
Dexron III(H) uses older Anti-Wear chemistry. Dexron VI uses modern Anti-Wear chemistry.
What brand Dex III are they using?
Are you referring to the stats comments?
If so, it was GM Dexron III(H) vs GM Dexron VI.
Dexron III(H) was the last Dexron III specification.
Dexron/Merc fluids today use an additive package that conforms to the old Dexron III(H).
The Dexron III(H) and the Dexron VI has about the same dynamic coefficients of friction for the wet clutches.
The major difference is that Dexron VI contains a more stable additive package and a better mix of base oils than did Dexron III(H). The minor difference is the starting viscosity but the Dexron VI shears much less than the old Dexron III.
I question any statement that says a 1.4 cSt difference in starting viscosity in a well functioning transmission will make a difference.
Originally Posted by MolaKule
...Let's look at some of the Dexron III(H) and Dexron VI stats. Dexron III(H) is 1.4 cSt higher at 100C than Dexron VI but:
Starting Viscosities@100C
exron III(H) 7.3 cSt, Dexron VI - 5.9 cStShear Stability (~ 10k miles): Dexron III(H) - 4.5 cSt, Dexron VI - 5.8 cSt
Shear Stability .(>=35k): Dexron III(H) - 4.3 cSt, Dexron VI - 5.5 cSt
Dexron III(H) has dropped over 2.8 cSt while Dexron VI has remained stable with only a 0.4 cSt drop. Dexron VI is superior in terms of viscosity stability.
Friction Modification Stability: In Dyno tests, Dynamic friction coefficient change: Dexron III(H) -~ 3%, Dexron VI - ~ 0.05%. Dexron VI is superior in terms of Dynamic friction coefficient stability.
Dexron III(H) uses older Anti-Oxidant and Metal Inhibitor chemistry. Dexron VI uses modern Anti-Oxidant and Metal Inhibitor chemistry.
Dexron III(H) uses older Anti-Wear chemistry. Dexron VI uses modern Anti-Wear chemistry.
What brand Dex III are they using?
Are you referring to the stats comments?
If so, it was GM Dexron III(H) vs GM Dexron VI.
Dexron III(H) was the last Dexron III specification.
Dexron/Merc fluids today use an additive package that conforms to the old Dexron III(H).
The Dexron III(H) and the Dexron VI has about the same dynamic coefficients of friction for the wet clutches.
The major difference is that Dexron VI contains a more stable additive package and a better mix of base oils than did Dexron III(H). The minor difference is the starting viscosity but the Dexron VI shears much less than the old Dexron III.
I question any statement that says a 1.4 cSt difference in starting viscosity in a well functioning transmission will make a difference.
Last edited:
So, in comparison, what about the market niche for products like Mobil 1 ATF and Pennzoil Platinum High Mileage Fully Synthetic ATF? These have fully synthetic base stocks and the fluid manufacturers recommend these for DexIII / Mercon applications with an in-the-bottle viscosity in the DexIII range.
Will these formulations maintain their operating viscosity longer than a currently available conventional DexIII / Mercon fluid, or will they lose viscosity due to shear just as quickly as conventional DexIII / Mercon ATF formulations?
Will these formulations maintain their operating viscosity longer than a currently available conventional DexIII / Mercon fluid, or will they lose viscosity due to shear just as quickly as conventional DexIII / Mercon ATF formulations?
Last edited:
MolaKule
Staff member
Originally Posted by Nyogtha
So, in comparison, what about the market niche for products like Mobil 1 ATF and Pennzoil Platinum High Mileage Fully Synthetic ATF? These have fully synthetic base stocks and the fluid manufacturers recommend these for DexIII / Mercon applications with an in-the-bottle viscosity in the DexIII range.
Will these formulations maintain their operating viscosity longer than a currently available conventional DexIII / Mercon fluid, or will they lose viscosity due to shear just as quickly as conventional DexIII / Mercon ATF formulations?
Those that use the additive package that conforms to the old Dexron III(H) may have a slighty longer life, due to improved base oil anti-oxidation, but will not have the shear nor the friction modifier stability.
Some of the botique ATF manf. are using an equivalent Dexron VI additive package with their full synthetic base oils so those ATF's should show the same, if not better, long term stability. Of course, their prices tend to reflect this as well.
So, in comparison, what about the market niche for products like Mobil 1 ATF and Pennzoil Platinum High Mileage Fully Synthetic ATF? These have fully synthetic base stocks and the fluid manufacturers recommend these for DexIII / Mercon applications with an in-the-bottle viscosity in the DexIII range.
Will these formulations maintain their operating viscosity longer than a currently available conventional DexIII / Mercon fluid, or will they lose viscosity due to shear just as quickly as conventional DexIII / Mercon ATF formulations?
Those that use the additive package that conforms to the old Dexron III(H) may have a slighty longer life, due to improved base oil anti-oxidation, but will not have the shear nor the friction modifier stability.
Some of the botique ATF manf. are using an equivalent Dexron VI additive package with their full synthetic base oils so those ATF's should show the same, if not better, long term stability. Of course, their prices tend to reflect this as well.
MolaKule
Staff member
One other specification I neglected to mention is that of the Brookfield viscosity at -40C for the Dexron VI has to be at least 5000 units lower than the Dexron III(H) or Dex/Merc.
This means the Dexron VI has better cold temperature operation than does the Dexron III(H) or Dex/Merc.
This means the Dexron VI has better cold temperature operation than does the Dexron III(H) or Dex/Merc.
Last edited:
Sounds like I'm best off sticking with dexron 6, especially since it seems to have no negative effects on any of my old transmissions. This morning was a minus 23 celsius cold start. My starter solenoid actually grinded for the first second or so before engaging and rolling the engine over very slowly. Made me wish I had the 0w30 instead of 5w30 today.
Originally Posted by caprice_2nv
This morning was a minus 23 celsius cold start. My starter solenoid actually grinded for the first second or so before engaging and rolling the engine over very slowly. Made me wish I had the 0w30 instead of 5w30 today.
Actually at that temperature there is little difference between a 5W and a 0W rated oil.
This morning was a minus 23 celsius cold start. My starter solenoid actually grinded for the first second or so before engaging and rolling the engine over very slowly. Made me wish I had the 0w30 instead of 5w30 today.
Actually at that temperature there is little difference between a 5W and a 0W rated oil.
Originally Posted by MolaKule
Originally Posted by Nyogtha
So, in comparison, what about the market niche for products like Mobil 1 ATF and Pennzoil Platinum High Mileage Fully Synthetic ATF? These have fully synthetic base stocks and the fluid manufacturers recommend these for DexIII / Mercon applications with an in-the-bottle viscosity in the DexIII range.
Will these formulations maintain their operating viscosity longer than a currently available conventional DexIII / Mercon fluid, or will they lose viscosity due to shear just as quickly as conventional DexIII / Mercon ATF formulations?
Those that use the additive package that conforms to the old Dexron III(H) may have a slighty longer life, due to improved base oil anti-oxidation, but will not have the shear nor the friction modifier stability.
Some of the botique ATF manf. are using an equivalent Dexron VI additive package with their full synthetic base oils so those ATF's should show the same, if not better, long term stability. Of course, their prices tend to reflect this as well.
So the guiding factor for the retail comsumer as to which DexIII compatible fluids with synthetic base stocks and DexVI additive package is price?
What about products such as Pennzoil Platinum High Mileage Fully Synthetic ATF that didn't exist before 2005? It has a typical retail price lower than Mobil 1 ATF, but Mobil 1 ATF existed before 2005 IIRC.
Regarding the Brookfield vis specs, it appears XOM gets around this by using the term "recommended for DexIII / Merc applications" rather than "meets DexIII / Merc specifications". Otherwise the Brookfield vis specs would appear to be mutually exclusive with use of synthetic base stocks.
https://www.mobil.com/English-US/Passenger-Vehicle-Lube/pds/GLXXMobil-1-Synthetic-ATF
https://www.mobil.com/english-us/passenger-vehicle-lube/pds/glxxmobil-atf-dm
I'll add the only time I bought M1 ATF was at end of year closeout at Autozone for $2 / qt a few years back for a friend's 4T65E, it was the same price as Super Tech conventional DexIII / Merc at that limited time window.
Originally Posted by Nyogtha
So, in comparison, what about the market niche for products like Mobil 1 ATF and Pennzoil Platinum High Mileage Fully Synthetic ATF? These have fully synthetic base stocks and the fluid manufacturers recommend these for DexIII / Mercon applications with an in-the-bottle viscosity in the DexIII range.
Will these formulations maintain their operating viscosity longer than a currently available conventional DexIII / Mercon fluid, or will they lose viscosity due to shear just as quickly as conventional DexIII / Mercon ATF formulations?
Those that use the additive package that conforms to the old Dexron III(H) may have a slighty longer life, due to improved base oil anti-oxidation, but will not have the shear nor the friction modifier stability.
Some of the botique ATF manf. are using an equivalent Dexron VI additive package with their full synthetic base oils so those ATF's should show the same, if not better, long term stability. Of course, their prices tend to reflect this as well.
So the guiding factor for the retail comsumer as to which DexIII compatible fluids with synthetic base stocks and DexVI additive package is price?
What about products such as Pennzoil Platinum High Mileage Fully Synthetic ATF that didn't exist before 2005? It has a typical retail price lower than Mobil 1 ATF, but Mobil 1 ATF existed before 2005 IIRC.
Regarding the Brookfield vis specs, it appears XOM gets around this by using the term "recommended for DexIII / Merc applications" rather than "meets DexIII / Merc specifications". Otherwise the Brookfield vis specs would appear to be mutually exclusive with use of synthetic base stocks.
https://www.mobil.com/English-US/Passenger-Vehicle-Lube/pds/GLXXMobil-1-Synthetic-ATF
https://www.mobil.com/english-us/passenger-vehicle-lube/pds/glxxmobil-atf-dm
I'll add the only time I bought M1 ATF was at end of year closeout at Autozone for $2 / qt a few years back for a friend's 4T65E, it was the same price as Super Tech conventional DexIII / Merc at that limited time window.
Originally Posted by Nyogtha
Regarding the Brookfield vis specs, it appears XOM gets around this by using the term "recommended for DexIII / Merc applications" rather than "meets DexIII / Merc specifications". Otherwise the Brookfield vis specs would appear to be mutually exclusive with use of synthetic base stocks.
They can't say it is a dexron III product since that licensing is no longer available. All of them must say it is "suitable" or "recommended" for.
Regarding the Brookfield vis specs, it appears XOM gets around this by using the term "recommended for DexIII / Merc applications" rather than "meets DexIII / Merc specifications". Otherwise the Brookfield vis specs would appear to be mutually exclusive with use of synthetic base stocks.
They can't say it is a dexron III product since that licensing is no longer available. All of them must say it is "suitable" or "recommended" for.
So Mr. Kule's point doesn't really apply to properties for a synthetic base oil DexIII / Merc compatible ATF (with DexIII /Merc in-the-bottle starting viscosity) other than these will have similar cold performance improvements as a synthetic base stock DexVI formulated fluid vs original DexIII / Merc specs for Brookfield viscosity.
Last edited:
![[Linked Image]](http://i.imgur.com/qApEOTt.jpg "[Linked Image]")
![[Linked Image]](http://i.imgur.com/dgnqqH3.jpg "[Linked Image]")
Last edited:
AMSOIL offers both Signature Series and OE Series ATF that is not low viscosity... It's called "Multi-Vehicle" rather than "Fuel-Efficient"... Another option is Royal Purple Max-ATF.
Those are excellent choices for vehicles that were made before low viscosity ATFs were introduced.
Those are excellent choices for vehicles that were made before low viscosity ATFs were introduced.
Originally Posted by alcyon
I havs used that fluid with no issues but I seemed to have no issues with any of them. All of my issue were back around 120k and after several 30k mile flushes all the problems went away.
I havs used that fluid with no issues but I seemed to have no issues with any of them. All of my issue were back around 120k and after several 30k mile flushes all the problems went away.
Originally Posted by MolaKule
Originally Posted by hatt
Originally Posted by MolaKule
...Let's look at some of the Dexron III(H) and Dexron VI stats. Dexron III(H) is 1.4 cSt higher at 100C than Dexron VI but:
Starting Viscosities@100Cexron III(H) 7.3 cSt, Dexron VI - 5.9 cSt
Shear Stability (~ 10k miles): Dexron III(H) - 4.5 cSt, Dexron VI - 5.8 cSt
Shear Stability .(>=35k): Dexron III(H) - 4.3 cSt, Dexron VI - 5.5 cSt
Dexron III(H) has dropped over 2.8 cSt while Dexron VI has remained stable with only a 0.4 cSt drop. Dexron VI is superior in terms of viscosity stability.
Friction Modification Stability: In Dyno tests, Dynamic friction coefficient change: Dexron III(H) -~ 3%, Dexron VI - ~ 0.05%. Dexron VI is superior in terms of Dynamic friction coefficient stability.
Dexron III(H) uses older Anti-Oxidant and Metal Inhibitor chemistry. Dexron VI uses modern Anti-Oxidant and Metal Inhibitor chemistry.
Dexron III(H) uses older Anti-Wear chemistry. Dexron VI uses modern Anti-Wear chemistry.
What brand Dex III are they using?
Are you referring to the stats comments?
If so, it was GM Dexron III(H) vs GM Dexron VI.
Dexron III(H) was the last Dexron III specification.
Dexron/Merc fluids today use an additive package that conforms to the old Dexron III(H).
The Dexron III(H) and the Dexron VI has about the same dynamic coefficients of friction for the wet clutches.
The major difference is that Dexron VI contains a more stable additive package and a better mix of base oils than did Dexron III(H). The minor difference is the starting viscosity but the Dexron VI shears much less than the old Dexron III.
I question any statement that says a 1.4 cSt difference in starting viscosity in a well functioning transmission will make a difference.
They were testing old fluid that's no longer made against modern product? How does the current crop of Dex/Merc perform?
Originally Posted by hatt
Originally Posted by MolaKule
...Let's look at some of the Dexron III(H) and Dexron VI stats. Dexron III(H) is 1.4 cSt higher at 100C than Dexron VI but:
Starting Viscosities@100C
exron III(H) 7.3 cSt, Dexron VI - 5.9 cStShear Stability (~ 10k miles): Dexron III(H) - 4.5 cSt, Dexron VI - 5.8 cSt
Shear Stability .(>=35k): Dexron III(H) - 4.3 cSt, Dexron VI - 5.5 cSt
Dexron III(H) has dropped over 2.8 cSt while Dexron VI has remained stable with only a 0.4 cSt drop. Dexron VI is superior in terms of viscosity stability.
Friction Modification Stability: In Dyno tests, Dynamic friction coefficient change: Dexron III(H) -~ 3%, Dexron VI - ~ 0.05%. Dexron VI is superior in terms of Dynamic friction coefficient stability.
Dexron III(H) uses older Anti-Oxidant and Metal Inhibitor chemistry. Dexron VI uses modern Anti-Oxidant and Metal Inhibitor chemistry.
Dexron III(H) uses older Anti-Wear chemistry. Dexron VI uses modern Anti-Wear chemistry.
What brand Dex III are they using?
Are you referring to the stats comments?
If so, it was GM Dexron III(H) vs GM Dexron VI.
Dexron III(H) was the last Dexron III specification.
Dexron/Merc fluids today use an additive package that conforms to the old Dexron III(H).
The Dexron III(H) and the Dexron VI has about the same dynamic coefficients of friction for the wet clutches.
The major difference is that Dexron VI contains a more stable additive package and a better mix of base oils than did Dexron III(H). The minor difference is the starting viscosity but the Dexron VI shears much less than the old Dexron III.
I question any statement that says a 1.4 cSt difference in starting viscosity in a well functioning transmission will make a difference.
They were testing old fluid that's no longer made against modern product? How does the current crop of Dex/Merc perform?
The more you know... Ive been putting DexIII in my Jeeps AW4. Next time I will change over to Dex VI.
Though looking at the prices DexVI is 2x the price at some places
Though looking at the prices DexVI is 2x the price at some places
Last edited:
MolaKule
Staff member
Originally Posted by hatt
...They were testing old fluid that's no longer made against modern product? How does the current crop of Dex/Merc perform?
That would be an interesting exercise for some institution with a large budget.
I don't think PQIA could do it as they only do elemental and viscosity testing within their budgetary constraints. One could could farm-out the Fuel Injector Shear Stability test, the Sonic shear test, the DEXRON®-III Cycling test, and KRL test to outside lab(s).
...They were testing old fluid that's no longer made against modern product? How does the current crop of Dex/Merc perform?
That would be an interesting exercise for some institution with a large budget.
I don't think PQIA could do it as they only do elemental and viscosity testing within their budgetary constraints. One could could farm-out the Fuel Injector Shear Stability test, the Sonic shear test, the DEXRON®-III Cycling test, and KRL test to outside lab(s).
Last edited:
- Status
