AMSOIL ATF MERCON SP & DEXRON VI EXPALINATION

[Don Stefanik]

AMSOIL Automotive Applications - ATF

Q. How can AMSOIL Universal Automatic Transmission Fluid (ATF) with a viscosity of 6.8 cSt be recommended for DEXRON VI and MERCON SP with respective maximum viscosities of 6.5 and 6.0 and also be recommended for ATF+4 with a minimum viscosity of 7.3?

A. AMSOIL positioned the viscosity of the AMSOIL Universal Automatic Transmission Fluid in the middle of most of the specifications from many manufacturers. These specifications include:

GM DEXRON II, III & VI
Ford MERCON, MERCON V & MERCON SP
Chrysler ATF+ thru ATF+4
Honda Z-1 (not CVT)
Toyota Type T & TIV
Mitsubishi/Hyundai Diamond SP II & III
Allison C-3, C-4
Caterpillar TO-2
Voith G 607 & G1363
ZF TE-ML 14A, B & C
MB 236.1, 236.2, 236.6, 236.7, 236.9
BMW 7045E
JWS 3309
LT 71141 (ESSO)
NAG 1 & 2
Nissan Matic D, J & K
Vickers I 286S & M2950S
For years original equipment manufacturers (OEMs) were primarily concerned with efficiencies at cold temperatures. Cold temperature performance of fluidity is measured by the Brookfield viscosity in Centipoises (cP) at -40°C (See chart 1). Chart 1 provides the maximum viscosity allowed at -40°C. This insures proper flow of lubrication to internal components at cold temperature for good lubrication.

(Chart 1)

ATF Brookfield Viscosity (cP) Comparisons

MERCON

MERCON V

Mercon SP

DEXRON III

DEXRON VI

Chrysler ATF+4

AMSOIL ATF
9,326


As of recent, OEMs have begun to regulate the maximum viscosity of the oil. It is generally accepted that thinner oils improve operating efficiency. By limiting the upper viscosity, such as with DEXRON VI and MERCON SP, OEMs are trying to capture the additional efficiency, no matter how small it may be. The two newest specifications, DEXRON VI and MERCON SP, have a starting viscosity maximum of 6.0 cSt and 6.5 cSt respectively. Although AMSOIL ATF at 6.8 cSt has a slightly higher viscosity than MERCON SP and DEXRON VI and a slightly lower viscosity than ATF+4 (7.3 cSt), it does not negatively affect performance in any of those applications. With respect to MERCON SP and DEXRON VI, AMSOIL ATF fulfills the cold temperature requirements so the marginally higher viscosity of 0.3 to 0.8 cSt will only provide better protection. With respect to DEXRON III, MERCON V and ATF+4, our experience has shown that conventional oils may shear down to below 5 cSt during use. Additionally, DEXRON VI is recommended as a replacement for DEXRON III so the lighter viscosity for AMSOIL ATF is immaterial.

AMSOIL recommendations are based on sound technical principles. Because of its superior base oil technology, AMSOIL ATF fulfills the important cold temperature requirement and its inherently high viscosity index contributes to a higher base oil viscosity and ultimate shear stability. AMSOIL ATF is compatible with all the seal materials and its oxidation and frictional properties are extremely stable. AMSOIL ATF is perfectly positioned to work in all the listed applications.

 

[KBFXDLI]

6.8 is higher than 6.0 Amsoil doesn't meet the spec for Dexron VI. Even though they say so. Technical spec.s are not made to be bent. Even though Amsoil would like to have an ATF that does all things to all people in all applications it doesn't work that way. The relation of Amsoil ATF to DEXIII is irrelevant with it's relationship to DEXVI. Because DEXVI is backwards compatible with DEXIII applications does not change the GM spec. of 6.0

 

[ConfederateTyrant]

Amsoil may not meet the spec but it's obvious their testing has deemed it suitable for the Dexron VI, as well as Mercon SP, applications by their own recommendation, which could mean a world of trouble for Amsoil Inc. if they are wrongly recommending.

Looking forward to hearing some feedback on people who are using this in Dexron VI and Mercon SP spec'd equipment.

 

[KBFXDLI]

I didn't say it wouldn't work...I said it doesn't meet the GM spec. Which it doesn't. Whether your GM vehicle application will ever hit the temperature or conditions where that spec is tested is strictly conjecture. A guy in Texas might be fine with it while a guy in Michigan might experience excessive clutch wear and never know it until he is well out of warranty who knows. The GMT900 series vehicles have not even been out 1 year yet...who could have relevant data? Plus how much in vehicle testing could Amsoil possibly have done that GM did not? But they are tellin people that they meet a spec that they don't. That is my beef with the Amsoil people.

 

[Pablo]

Amsoil is not telling people they meet the specification. Hence the statement.

 

[unDummy]

Like 1 cSt makes a difference

Look at the visc span for typical 20wts(5.6-9.3), 30wts(9.3-12.5), and 40wts(12.5-16.3). Does anyone argue the 3.2+ point spread in label motor oil weights?

But, the synthetics have had the cold flow specs trumped over a decade or 2 ago. Some transmission are a little cranky when cold. Improved cold flow performance helps reduce that issue. Some of the new OEM specs are still lacking compared to the 20 year aftermarket boutique specs. This is one reason why I've been using boutique fluid for the past 2 decades.

BTW, the M1 ATF and Redline D4 have ~5000cst at -40 specs. I can't wait to see Redline D6!

Since transmissions rarely operate at 212F, why even argue?
Most transmissions operate between outdoor/garage temp and 160F. Some will climb to 180f when stressed. If a ATF is seriously pushed to 212F+, I myself would want a thicker ATF for protection, especially in a 'worked' vehicle. In a daily driver, its a coin toss.

If you want the most MPG, then please use the thinnest D-VI. But, don't slam Amsoil for coming out with a univeral ATF. The 1/2 point cst is a meaningless argument.

Gotta run. The old C6 is low on ATF. Need to top it off with anti-MPG offend the treehugger ~8.5 cst Dexron.

 

[Pablo]

unDummy name fits a person who writes with such wisdom.

 

[fred0803]

Quote:

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Amsoil is not telling people they meet the specification. Hence the statement.

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Exactly stated.
That's what people confuse on here. Because a manufacturer states is "can be used or is suitable for" a specific fluid doesn't mean it is.
I have no doubt that Amsoil univeral ATF is good fluid. It's just if your car is under warranty, then go with whatever the dealer is telling you to use. Good way to void a warranty.

 

[ConfederateTyrant]

Quote:

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anti-MPG offend the treehugger ~8.5 cst Dexron

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[Gary Allan]

Quote:

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Because a manufacturer states is "can be used or is suitable for" a specific fluid doesn't mean it is.

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Well ..I'd say the opposite. It clearly states that it's suitable for use. What it doesn't say is that it matches OEM specifications in either material composition or properties. Which, in the vendors authoritative opinion, don't alter the functional properties of the fluid in the applications that it covers.

As in the aforementioned example ..if you're using the minor visc differences as justification for rejection of the suitability of the fluid for use in a specific application ..and the same OEM spec'd fluid spans -40 to +110 ambient ..both are going to span every conceivable visc due to temp variations. Tow? Same deal. Moot point except for irrational nitpicking.

That's not to say that some irrational nitpicker may be an alleged authority...but the nitpicking will still be totally irrational.

 

[Pablo]

I think an ATF viscosity graph would be cool right about now.

Any volunteers?

 

[Whitewolf]

I'm afraid Don is confusing spec limits with actual test results. The limits are one thing but the fluids are generally blended to be INSIDE the limits so comparing the limits with the Amsoil result is in my view misleading. This is and always will be the problem with unqualified fluids, no one knows how they really perform and although there are claims that some of these fluids exceed the spec, no data is usually shown in a manner that permits a true A/B comparison.

 

[Pablo]

True enough Whitewolf in some aspects - but the real point is that Amsoil meets those cold temp viscosity specifications. People are concerned that Amsoil ATF will be too viscous at low (and other) temps - this is simply not the case.

Again a viscosity curve of all the ATF's in question would be GREAT!

 

[GMorg]

Well, for Amsoil ATF (new version) verses Petro Canada Dexron VI, here are the viscosities (cSt) at a range of temperatures (C). When it is really cold, Amsoil will be less viscous than factory fill Dex VI.

Code:

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temp amsoil petrocanada

-40 8820 9535

-20 1074 1052

0 237 220

20 77 70.2

40 33.5 29.8

60 17.4 15.4

80 10.4 9.1

100 6.8 6

120 4.8 4.24

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[Brett Miller]

I think Amsoil would have been better served by leaving the formula alone and bringing out another formula that is Dexron IV and Mercon SP compatible.

 

[Whitewolf]

OK, can you now tell us what is the range of blend repeatability and on top of that what is the test repeatability?
Really the only thing that stands out is that the Amsoil fluid fails to meet the GM spec on Kinimatic viscosity.

 

[GMorg]

I know that I can't tell you what the lot/batch variation is on either fluid. Likewise, I cannot tell you what the standard error is on the measurement. However, I can tell you that one would be in error to say that Amsoil ATF is "thicker" than DexVI at very cold temperatures. What stands out for me is that people can authoritatively spew errors and it is very well tolerated.

 

[TeeDub]

The key concerns are meeting/exceeding the low temp pumpability limits and maintaining a stable viscosity and frictional properties over time. This will ensure consistent shift quality as the fluid ages.

As a practical matter, even a slight variation (10F-15F), in ATF temps will have a much greater effect on the working viscosity of the fluid in the transmission, compared to this difference in baseline properties.

This Q & A makes perfect sense to me....

TD

 

[Pablo]

Thanks for posting the numbers gmorg. Who needs a graph when a nice table drives the point home perfectly!! TeeDub shows up with precision timing and drives it OUT OF THE PARK!!!

For someone to say Amsoil ATF won't work because the kinematic viscosity is 6.8 cSt@100°C, well that's just not right and they know it.

 

[PT1]

Quote:

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Well, for Amsoil ATF (new version) verses Petro Canada Dexron VI, here are the viscosities (cSt) at a range of temperatures (C). When it is really cold, Amsoil will be less viscous than factory fill Dex VI.

Code:

---

temp amsoil petrocanada

-40 8820 9535

-20 1074 1052

0 237 220

20 77 70.2

40 33.5 29.8

60 17.4 15.4

80 10.4 9.1

100 6.8 6

120 4.8 4.24

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Looks quite the opposite to me based on this chart...since most "cold" operating temps in the Northern parts (ex Alaska) are in the 0-40F range. Our engineering analysis based on this chart would disqualify the amsoil fluid.