DEXIII Mercon -vs- MerconV flash point

[hominid7]

Why is it when looking at the PDS sheets for various ATF's the flash point of several DexIII/Mercon ATF's seem to be higher than the flash point of most MerconV's?

In addition, Supertech (WPP) seems to have one of the highest flash points?!?

If heat is the ultimate killer of ATX's then why are we moving to lower flash points? Do the newer fluids keep the transmissions cooler and thus dont need such a high flash point? Or is it because the newer blend ATF's are thinner and thus just have a lower flash point to begin with?

 

[DoubleAces]

The flash point specification for MERCON and MERCON V are identical (>177C). I'm surprised that you are seeing lower flash points for MERCON V fluids. Regarding your comment on lower viscosity fluids and flash point, the flash point spec for DEXRON-VI is >180C, and DEXRON-VI has a lower 100C viscosity than either MERCON or MERCON V.

 

[hominid7]

It's always possible the PDS sheets are out of date and/or not accurate, but if we look at the Pennzoil sheets we find:

DexIII/Mercon
Flash = 204*C

Penz MultiVehicle Synthetic Blend
Flash = 190*C

I was contemplating switching from my current Pennzoil DexIII/Mercon to the Pennzoil Multi Vehicle blend, but with a lower flash point i'm not so sure it would be forward progress other than better flow at cold temps. Considering i live in Texas, we just dont see -40* around here

 

[unDummy]

Its a meaningless measurement. If your ATF ever reaches flashpoint, your transmission is already toast.

Flashpoint measurement accuracy isn't perfect. Some of the ATF's list a flashpoint in the spec sheet, but then list a flashpoint 'range' in the MSDS.

Something as simple as a flash-point supressant can be added to a lower quality fluid to help it perform better. But does that last as long or perform as well as a fluid with better a basestock to begin with?

Actual performance in a transmission is more important then any 'single' comparison specs.

IMO, for hotter weather, the ATF's anti-shear performance is more important then flashpoint.
Mercon-V and multivehicles ATFs have always performed better then dexron/mercon in automatics that I've used them in.

 

[hominid7]

UnDummy: Thanks for the info. I was certain there was someting i was missing as it just didn't seem to make sense. My transmission has never given me any problems, but since the design has a somewhat spotty record I'm just looking for ways to keep it trouble free.

Now for my next pondry, is fresh DexIII/Mercon + LubeGuard Red better or worse than MerconV alone?